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EAI/Springer Innovations in
Communication and Computing

Series Editor
Imrich Chlamtac
European Alliance for Innovation, Ghent, Belgium

Editor’s Note
The impact of information technologies is creating a new world yet
not fully understood. The extent and speed of economic, life style and
social changes already perceived in everyday life is hard to estimate
without understanding the technological driving forces behind it. This
series presents contributed volumes featuring the latest research and
development in the various information engineering technologies that
play a key role in this process.
The range of topics, focusing primarily on communications and
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networks; mobile communication; design and learning; gaming;
interaction; e-health and pervasive healthcare; energy management;
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cloud computing; ubiquitous connectivity, and in mode general smart
living, smart cities, Internet of Things and more. The series publishes a
combination of expanded papers selected from hosted and sponsored
European Alliance for Innovation (EAI) conferences that present
cutting edge, global research as well as provide new perspectives on
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open calls for contribution of book titles and individual chapters,
together maintain Springer’s and EAI’s high standards of academic
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specialists, security experts, economists, urban planners, doctors, and
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Indexing: This series is indexed in Scopus, Ei Compendex, and
zbMATH.
About EAI
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competitiveness and link the European Research community with its
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Through its open free membership model EAI promotes a new
research and innovation culture based on collaboration, connectivity
and recognition of excellence by community.
More information about this series at http://​www.​springer.​com/​
series/​15427
Editors
M. Kathiresh and R. Neelaveni

Automotive Embedded Systems

Key Technologies, Innovations, and Applications
1st ed. 2021
Editors
M. Kathiresh
Department of Electrical and Electronics Engineering, PSG College of
Technology, Coimbatore, Tamil Nadu, India

R. Neelaveni
Department of Electrical and Electronics Engineering, PSG College of
Technology, Coimbatore, Tamil Nadu, India

ISSN 2522-8595 e-ISSN 2522-8609

EAI/Springer Innovations in Communication and Computing
ISBN 978-3-030-59896-9 e-ISBN 978-3-030-59897-6
https://doi.org/10.1007/978-3-030-59897-6

© Springer Nature Switzerland AG 2021

This work is subject to copyright. All rights are reserved by the

Publisher, whether the whole or part of the material is concerned,
specifically the rights of translation, reprinting, reuse of illustrations,
recitation, broadcasting, reproduction on microfilms or in any other
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electronic adaptation, computer software, or by similar or dissimilar
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service marks, etc. in this publication does not imply, even in the
absence of a specific statement, that such names are exempt from the
relevant protective laws and regulations and therefore free for general
use.

The publisher, the authors and the editors are safe to assume that the
advice and information in this book are believed to be true and accurate
at the date of publication. Neither the publisher nor the authors or the
editors give a warranty, expressed or implied, with respect to the
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Switzerland
Preface
Over the last two decades, various functions of a vehicle are performed
by using electrical and electromechanical systems, which were
performed by mechanical linkages in conventional automotive systems.
The concept of using electronic control systems as replacement for
mechanical control systems in automobiles is called as drive-by-wire or
x-by-wire. The main functions such as acceleration, braking, and
steering are controlled by the use of mechanical, pneumatic, and
hydraulic components in conventional vehicles where are more prone
to wear and tear. Thus, the efficiency and performance of such vehicles
deteriorates over a period of time. In contrast, the drive-by-wire
technology uses sensors, electrical motors, and electromechanical
actuators to perform vehicular functions. Moreover, the subsystems in
the drive-by-wire technology have a dedicated Electronic Control Unit
(ECU) to monitor and control vehicle parameters with the help of
appropriate sensors and actuators. These subsystems are called as
Automotive Embedded Systems. Embedded systems in automobiles are
basically classified into five domains such as Power Train, Body
Electronics, Chassis, Human–Machine Interface, and Telematics.
The main objective of Industry 4.0, the Fourth Industrial Revolution
is to make everything smart and connected with each other. The
tremendous growth in automotive electronics and wireless
communication technology has paved a way for new technology called
Connected Cars through which many innovative features have been
added in a typical car to enhance the comfort of the stake holders.
This book starts with automotive safety systems which is one of the
major functional domains. The book discusses the importance of
software in automotive systems followed by an insight into Automotive
Software Standards, MISRA Coding Standards, and Model-based
Software Development Approach. The book further discusses vehicle
diagnostics and over-the-air software update processes. The book also
illustrates the role of sensors and artificial intelligence in automotive
systems. Various innovative applications involving the concept of
Internet of Things are also presented in this book. This book is
intended for academicians, researchers, and industrialists.
M. Kathiresh
 R. Neelaveni
Coimbatore, Tamil Nadu, India
Coimbatore, Tamil Nadu, India
Acknowledgment
We would like to thank Mr. Imrich Chlamtac, the Series Editor and Ms.
Eliska, the Managing Editor at European Alliance for Innovation, for
giving us this opportunity to edit a book in the Series of Innovations in
Communication and Computing, Springer. We express our sincere
thanks to the authors for their contribution and whole-hearted
cooperation in the making of this book. We also thank the reviewers for
their constructive criticism and comments which enriched this work.
We are grateful to PSG College of Technology, Coimbatore, India, for the
constant support and encouragement. Finally, we would like to
acknowledge with gratitude, the support, and love of our family
members and colleagues, without whom this book would not have been
possible.
Contents
Automotive Safety Systems
S. Hamsini and M. Kathiresh
Virtualizing an Automotive State-of-the-Art Microcontroller:​
Techniques and Its Evaluation
Arun Kumar Sundar Rajan and M. Nirmala Devi
AUTOSAR and MISRA Coding Standards
Y. Catherine Yamili and M. Kathiresh
Model-Based Automotive Software Development
K. Vinoth Kannan
Vehicle Diagnostics Over Internet Protocol and Over-the-Air
Updates
M. Kathiresh, R. Neelaveni, M. Adwin Benny and
B. Jeffrin Samuel Moses
Automotive Cybersecurity
Ashish Jadhav
Autonomous Vehicles:​Present Technological Traits and Scope for
Future Innovation
Arun S. Tigadi, Nishita Changappa, Shivansh Singhal and
Shrirang Kulkarni
Artificial Intelligence and Sensor Technology in the Automotive
Industry:​An Overview
S. Meenakshi Ammal, M. Kathiresh and R. Neelaveni
Advanced Driver Assistance Systems (ADAS)
Maria Merin Antony and Ruban Whenish
Analysis of IoT-Enabled Intelligent Detection and Prevention
System for Drunken and Juvenile Drive Classification
D. Ruth Anita Shirley, V. Kamatchi Sundari, T. Blesslin Sheeba and
S. Sheeba Rani
Internet of Things and Artificial Intelligence-Enabled Secure
Autonomous Vehicles for Smart Cities
 D. A. Janeera, S. Sheeba Rani Gnanamalar, K. C. Ramya and
A. G. Aneesh Kumar
Index
About the Editors
M. Kathiresh

is a Faculty in the Department of Electrical and

Electronics Engineering, PSG College of Technology, Coimbatore, India.

He has completed his Under Graduation in the stream of Electronics
and Communication Engineering, Post-Graduation in Embedded and
Real-Time Systems and Doctorate in the area of Automotive Embedded
Systems at Anna University, Chennai. He has done several innovative
projects which are now published in reputed journals, international
conferences, books, and some are patented. He has also carried out
many consultancy projects for various leading industries to help the
industries to adapt for Industry 4.0. He is currently working in a
research project funded by the Department of Science and Technology,
India. His research areas include Automotive Embedded Systems,
Internet of Things, and Real-Time Embedded Systems. He is a life
member of Institute of Engineers (India) and Indian Society of
Technical Education.

R. Neelaveni
 is presently working as Professor in the

Department of Electrical and Electronics Engineering, PSG College of

Technology, Coimbatore, India. She completed her Bachelor Degree in
Electronics and Communication Engineering (Madras University) and
Masters in Applied Electronics (Bharathiar University) from PSG
College of Technology, Coimbatore. She obtained her Ph.D. in
Biomedical Instrumentation from Bharathiar University, Coimbatore.
She has around 31 years of teaching experience. Her research interests
include Bio-signal processing, Bio-image processing, Computer
Networks, Soft computing, and Embedded Systems. She was awarded
the Best National Service Scheme Programme Officer of Anna
University, Chennai in the year 2004–2005. She has served as member
of Board of Studies in autonomous colleges and panel member for
faculty selection in various colleges. She has published many papers in
various reputed International Journals and Conferences. She also holds
patents and has contributed chapters in books. Currently, she is
working in a research project funded by the Department of Science and
Technology, India. She is a life member of Indian Society of Technical
Education.
© Springer Nature Switzerland AG 2021
M. Kathiresh, R. Neelaveni (eds.), Automotive Embedded Systems, EAI/Springer
Innovations in Communication and Computing
https://doi.org/10.1007/978-3-030-59897-6_1

Automotive Safety Systems

S. Hamsini1 and M. Kathiresh2
(1) Robert Bosch Engineering and Business Solutions Private Limited,
Coimbatore, India
(2) PSG College of Technology, Coimbatore, India

Keywords Active safety systems – Passive safety systems – Hardware

security – Software security – Network security – Driver assistance
systems

Introduction
Road traffic crashes lead to an estimated death of nearly 1.25 million
people in a year and millions more succumb to injuries [1]. In order to
reduce such gruesome road traffic fatalities and injuries, various
measures grounded on evidence have been formulated by the World
Health Organization. A critical role is played by safe vehicles to avert
crashes and minimize the probability of serious injury. Safety standards
for automobiles are set by the United Nations World Forum for
Harmonization of Vehicle Regulations along with the legal framework
for which voluntary application by member states is possible. Vehicles
that abide to these safety standards are less prone to accidents, and on
the occurrence of road traffic crashes, the injuries are far from life-
threatening [2].
Though there are various contributing factors to accidents, the
major single reason points towards the driver as human errors
contribute to a major percentile of accidents. Modern vehicles include
various safety features that assist the driver in various possible ways.
The modern vehicle design is focused on better safety features for the
driver and the passengers.
The systems that get activated in retribution to an abnormal event
such as a safety problem are termed as active safety systems. These
systems are triggered in anomalous circumstances by human operators
or spontaneously by an intelligent computer system. The systems that
act in a favorable manner in response to dangerous events by relying on
the laws of nature are named as passive safety systems. This safety
system may be a physical feature or an added internal system or design
modifications that enhance the driving of the vehicle.

Vehicle Safety Systems

When the design of a vehicle is considered, one amongst the various
important aspects is its safety both in the vehicle as well as in its
features. Automobile safety is the scientific domain related to the study,
design, construction, and regulation of technology mainly focused on
minimizing the occurrence and consequences of road traffic accidents.
Vehicle occupant safety can be generally categorized into two areas:
firstly, active safety, which is basically designed for crash avoidance, and
secondly, passive safety also known as crash worthiness where in the
worst case that a crash happens, protection of occupant is ensured [3].
The various active safety and passive safety features are depicted in Fig.
1.
Fig. 1 Active and passive safety features
The assistance provided by technology for the prevention of a crash
is termed as active safety, whereas the various physical components of
an automobile that collectively help to protect the inhabitants when a
crash occurs are referred as passive safety. Figure 2 illustrates the
timeline pertaining to the active safety and passive safety.
Fig. 2 Vehicle crash timeline of safety

Active Safety Systems

The features of a vehicle that help to mitigate or prevent road crashes
are basically active safety features. These features mainly focus on
prevention of the crash or reduction of severity of a crash that is
unavoidable in nature. One or more aspects of an automobile are
monitored constantly by the active safety features for potential hazards.
In the instance where a problem occurs, the situation is rectified
autonomously by active safety features. Protection that is offered is
increased by active safety features. The devices and systems used for
active safety are generally automated. Few basic active safety features
are discussed below.

Braking System
A brake is basically a mechanical device that operates by inhibiting
motion by means of absorbing energy from a moving object. It is
generally intended for decelerating or altogether stopping an
automobile in motion, its wheels and axle, and this is frequently
accomplished through friction. The rapid advancements in vehicles and
modern road infrastructure facilitate faster driving habits. In this
scenario, when hard brake is applied to a moving vehicle, the wheels
may get locked up and end up sending the vehicle to spin out of control.
In order to avoid those mishaps, an anti-skid system involving the brake
was developed which is now improved as Anti-Lock Braking System
(ABS).
Movement of vehicle is the result of friction between the vehicle’s
tyres and the road. A torque is applied in the opposite direction to that
of the friction, thus ultimately leading to the wheel halting the
rotations. While braking, ABS allows the vehicle’s wheels to maintain
tractive contact based on driver inputs with the road surface. Avoidance
of uncontrolled skidding and prevention of locking up of wheels are
attained.
The principles of threshold braking and cadence braking that were
in practice by experienced drivers formerly are employed in the ABS as
an automated system. Due to the automation, ABS acts in a
considerably faster rate and in a very effective manner than manual
operation. Enhanced vehicle control and reduced stopping distances is
provided by the ABS on dry and certain slippery surfaces, but the
performance is comparatively diminished, and the braking distance
may increase on loose gravel roads or surfaces concealed with snow.
Initially ABS was introduced for production vehicles; hence the
sophistication and effectiveness of these systems have increased. Not
only the prevention of wheel lock under braking is attained but also
alteration of the front-to-rear brake bias is accomplished. Illumination
of a warning light located on the vehicle instrument panel indicates a
fault within the ABS. Until the fault is resolved, the ABS will be
incapacitated. The modern ABS involves a dedicated microcontroller
controlling all the four wheels by means of a control system consisting
of hub-mounted sensors to apply individual brake pressure. Due to
rapid escalation of popularity of the electronic stability systems due to
the massive reduction in cost of vehicular electronics in the recent
years, the ABS is present as a standard entity in most of the vehicles
nowadays. A study has proved that automobiles with ABS are less likely
to go through fatal accidents by a percentage of 37%.
Brake lights are another feature of braking that is relatively less
technical and more of a handy feature while driving. Brake lights are
simple indicating lights usually red to enhance visibility even in
daytime. These lights glow brighter, indicating the vehicle following
that the brakes are applied and the vehicle is going to decelerate or
stop. It is more of a traffic feature that facilitates fellow drivers to adjust
to the traffic when someone applies brakes.
Parking brakes also known as hand brakes are another feature that
is used to secure the vehicle motionless when parked. The general idea
is to restrict the uncontrolled movement of the vehicle due to slope or
external impacts when parked, but historically it also acted as a
secondary emergency brake in situations where the main brake fails.
But with improved braking systems like ABS, the parking brakes are
needed only when the vehicle is parked.
As seen with the ABS and cruise control, the brake assist system
helps a driver in many ways from applying emergency brake pressure
to preventing collision and skidding. The modern brake assist is
integrated with an anti-collision system where brakes will apply
automatically on detecting a possibility of collision. It also gives
warnings about the health of brake system.

Visibility
Visibility to the driver is a major factor while plying on roads. Features
including rearview mirrors, wipers, and clear windshields enhance the
visibility for the driver to see.
Seating position of the driver is a key parameter as it decides the
visibility of the road and surroundings to the driver. One should choose
minimum or no blind spot position to sit while driving. Many features
like adjustable seat position, height, and adjustable steering columns
help in achieving a comfortable seating position for driving.
Though the feature of automatic climate control is more of a
comfort feature to control temperature and humidity inside the vehicle,
it also plays an important role in preventing formation of fog in
windows and windshields. Thus, it improves visibility during winters
and rainy season.
Rearview mirrors give access for the driver to see the sides and rear
side of the vehicle. It helps the driver to decide before changing lanes or
attempting a turn and helps to monitor the entire vehicle. Advanced
rearview mirrors also have features like electronic adjustments to
counter parallax errors and some vehicles have camera sensors that
capture the video and display it in the screen inside the vehicle.
 Headlamps facilitate the drivers to drive the vehicle during nights.
However, advanced features in headlamps such as adaptive focus and
brightness facilitate the driver with a better and comfortable visibility
[4].
Wipers are a simple link mechanism that helps in wiping the water
in the windshield while raining. During rains, it is difficult for the driver
to get proper visibility due to water creating refraction with the
windshield glass. Advanced features in wipers include automatic rain
sensing where the wiper gets activated on sensing raindrops on the
windshield.
There is another aspect of visibility where the vehicle needs to have
some added features to have better visibility to be seen by others.
Recent standards for vehicles after BS IV and Euro IV made it
mandatory for the vehicles to have running headlamps even during the
day. The idea is mainly to make the vehicle more visible even from a
distance. With advancements in headlamps after the introduction of
LEDs and their minimal cost for installation and maintenance, it is quite
a handy feature of the vehicle.
Parking lights are used when the vehicle is pulled over in highways
or some work is happening around the vehicle that is parked. It should
not be used when the vehicle is moving.
The color of a car has been a debatable study for the past decades as
to how it plays a role in road accidents. Some of the latest studies
essentially suggest that cars with brighter colors such as white are
relatively less prone to accidents than the ones with black or gray. Apart
from the study being under scrutiny to be proven factual, it is a general
idea that a better visible color enhances the visibility of the vehicle.
Another significant instance when it necessitates to get the
attention of fellow drivers on the road is especially when taking turns
or going reverse, and the accessories that aid for this are turning
indicators and reverse signal indicators. These indicators give the
signals by glowing intermittently, sometimes combined with a buzzer
or tune to alert the presence to fellow drivers.
Horns and tunes are used to grab the attention of fellow drivers to
indicate the action to be performed by the vehicle.

Minor Design Aspects

Bumpers fitted in front and the rear of the vehicle absorbs impacts
during minor collisions, preserving internal major components and
thereby reducing repair cost. However modern safety standards
suggest using soft bumpers to enhance pedestrian safety.
The intended design function of a spoiler which is an aerodynamic
device is to “spoil” hostile air movement across a moving vehicle,
generally termed as drag or turbulence. Spoilers employed in the front
of an automobile are termed as air dams. Spoilers are frequently
attached to sports cars of high performance and to vehicles intended
for racing, though nowadays it is a common accessory in passenger cars
too. Few spoilers that are employed in the cars are predominantly for
styling purposes and aid very less towards aerodynamics. The wing in a
vehicle refers to a device intended to generate downforce when air
passage occurs around it and to not disrupt the existing patterns of air
flow. Thus, instead of decreasing the drag, automotive wings in reality
increase drag.

Cruise Control
Cruise control also known as speed control automatically maintains the
speed of the vehicle by taking over the throttle of the vehicle and
maintains steady speed. This feature is especially helpful on highways
and expressways where a steady speed needs to be maintained over a
long period. Figure 3 illustrates the operation of cruise control system
present in vehicles.
Fig. 3 Cruise control
More advanced adaptive cruise control mechanisms integrate
features like radar-based dynamic cruise control and automatic braking
system on detecting potential forward collision, and this is essentially a
principal step towards autonomous vehicles where a vehicle varies its
speed through intelligent radar-based sensor system and also stops on
detecting collision probability with near-zero human interventions [5].
Speed governors are actually an optional feature which restricts the
vehicle from going beyond certain prescribed speed limits.
Autopilot is an advanced active safety feature envisioned for
advanced driver assistance to enhance the safety and convenience of
the driver behind the wheel. A few autopilot systems include a suite of
driver assistance features like traffic aware cruise control, auto lane
change, summoning where the car navigates in a parking lot to an
intended location while maneuvering around objects that hinder its
navigation otherwise and full self-driving capability among various
other features.

Stability
Physical stability of the vehicle is more of a design aspect of the vehicle
that provides mechanical stability to the vehicle while driving. Proper
wheel balancing, sturdy and rigid chassis, optimum tire pressure,
distribution of body weight, steering system, and suspensions majorly
contribute to the physical stability of the vehicle. Stringent standards
and guidelines are provided for the manufacturers to ensure these
design aspects [6].
Electronic stability control (ESC) is a computerized technology
which is intended to detect and reduce loss of traction that results in
skidding and thus overall improves the stability of a vehicle, and it is
also known as dynamic stability control (DSC) or electronic stability
program (ESP). Brakes are applied automatically when loss of steering
control is detected by ESC, and it steers the vehicle where it is supposed
to go according to the driver’s intention. Braking is applied
automatically to the wheels separately, namely, the outer wheel in the
front as a counter for steer and the inner wheel in the rear to handle
understeer. Engine power is also reduced by a few ESC systems till
control is attained. The cornering performance of the vehicle is not
improved by ESC, but the loss of control is minimized with its help. ESC
is a computerized system that involves various sensors such as wheel
speed sensors, steering angle sensor, accelerometer, etc.
A vehicle can be steered when it veers or slides out of the intended
path due to natural hindrances such as rain or snow. The path of a
vehicle in both the instances where ESC is present and not when loss of
traction occurs is depicted in the Fig. 4.

Fig. 4 Electronic stability control

 Traction control system is an active vehicle safety feature which is
actually a secondary feature of electronic stability control and kicks in
when the vehicle’s speed increases and prevents loss of traction of the
wheels driven on roads. This active safety feature is activated while
driving when the throttle input and the engine torque do not match.
Other key stability warnings are tyre deflation warnings which
prompts the driver that the tyres are either deflated or not in the
optimum pressure for the drive and air suspension warning system
which essentially warns about faulty functioning of suspension due to
various reasons.

Lane Departure Warnings

A lane departure warning system has the intended purpose of
monitoring the lane markings and detecting the drifting or veering of
vehicles out of its own lane. These systems then warn the drivers
through an audio alert or a visual illustration regarding the
unintentional lane shifts and to navigate the automobile back into its
intended lane. Figure 5 represents the lane departure warnings that
arise when the driver changes lanes along with the outline of the
current lane where the vehicle is navigating.

Fig. 5 Lane departure warnings

Park Assist and Reverse Assist
The most complicated aspect of driving involves parking of the vehicle
properly in a narrow space. Only skillful drivers can perform this
parking without much difficulty. Therefore, an assist to facilitate all the
drivers to park the vehicle is introduced in modern cars. The intelligent
park assist can steer itself into a parking space with no or minimum
input from the driver eliminating minor accidents. Another notable
feature is where the reverse assist essentially helps the driver to park
when the vehicle is put on reverse. It is integrated with a reverse
camera and sensors, and the view is displayed to the driver through a
screen that enables him to perform complex reverse maneuvers easily.
There are various sensors such as ultrasonic sensors to detect the
proximity of various objects within the vicinity of the vehicle in the rear
and warn about it.

Door Open Warning

Door open warning systems encompass a sensor that detects any
approaching vehicles in the rear when an individual is opening the car
door and prevents the opening of the car door when vehicles are
detected within the vicinity and also warns the approaching vehicle by
means of cautioning lights and buzzers. The door open warning system
is depicted in Fig. 6

Fig. 6 Door open warning

Dashboard Warning Signs for Various Aspects of
ECU and Component Failure
There are a lot of other warning signs in the dashboard that facilitate
the driver to have a tab over various aspects of the vehicle. Key features
include door not closed warning sign, low fuel indicators, seat belt
warnings, overheating of component or engine warnings, headlamp
status, indicator, and much more. Some the warning features in the
dashboard in a modern vehicle are illustrated as in Fig. 7

Fig. 7 Dashboard warning signs

Passive Safety Systems

Apart from various active safety features, there are many passive safety
features of the car which is also known as crashworthiness of the car.
These features are actual lifesavers when in unfortunate circumstances
the vehicle is subjected to a crash. Many crash tests are carried out on a
regular basis to improve the passive safety system that will reduce the
fatality rates even after the crash.
When a crash has occurred, then in that instance protection is
provided to the occupants from further injury through various features,
and these features are called as passive safety features. The protection
of the driver and passengers from several crash forces is ensured by the
passive safety features. Life space is the protected area surrounding the
occupants of the vehicle in which likelihoods of dodging with negligible
injuries are possible. Passive safety features help to ensure that the life
space exists safe and secure along with the occupants and they remain
in this space during the crash.

Airbags
Airbags are considered one of the most important and key safety
features nowadays. These airbags inflate into cushioning bags
essentially saving the driver and the passengers from the crash and
from sustaining fatal injuries. Advanced vehicles come with multiple
airbags to prevent injuries and to provide maximum protection. Even
though airbags do not offer complete protection, it reduces the impact
in such a way that the person has a better surviving chance.

Seat Belts
Seat belts along with the pretensioners prevent the person from
moving forward suddenly due to inertia when met with a forward
collision. This not only prevents the person from being ejected forward
but also holds them in a position for the airbags to operate effectively
for the safety. Wearing seat belts is mandatory for driving in almost
every country, and there are warning lights to indicate if the driver or
the driver side passenger doesn’t wear it. Modern vehicles include seat
belts for the passengers in the rear seats too.

Sturdy Front Design

Another important design feature is a sturdy and rigid front design
which will absorb most of the impact on the collision, so that the
person inside the vehicle can have better chance of surviving. Careful
placing of mounting brackets and other metal or sharp construction
away from the areas that are potential to hit the passengers is preferred
that in the off chance when a crash is inevitable. Preference is given to
leather or soft material usage in areas like dashboard, instrument
panel, and other areas of contact.
Non-shattering Windshields
The usage of laminated windshields enhances the visibility, but also the
glass comes with a non-shattering feature which breaks into minute
particles on crash, thereby avoid breaking into sharp pieces. This in
turn reduces the fatal injuries incurred during the crash.

Pedestrian Protective Soft Bumpers

This feature is to prevent sustaining injuries to the pedestrians who
may accidentally get hit by the vehicle. Hard front bumpers can inflict
severe injuries to the person who gets accidentally hit by the cars.
Therefore, relatively softer bumpers are preferred. Redesigning of
bumpers, hoods, and windshield to be energy absorbing will actually
reduce the impact on pedestrians during pedestrian-car crashes.

Collapsible Steering Column

Steering columns are found to be fatal in sustaining injuries to the
driver as it is rigid and immediately contacts the driver when in crash.
Therefore, a modification in the design has been brought in where the
columns automatically collapse down on high impact, thereby
preventing the driver from engaging with a rigid column on crashing.

Cargo Protection
Many SUVs, AUVs, and other utility vehicles have the feature to securely
fit the cargo, avoiding it from throwing off or moving while on crash.
This also helps from people suffering any injuries from heavy cargo or
luggage on the road.

Security
Automotive industry is inching towards superior integration and
virtualization by escalating the number of functions and complexity in
terms of the software. The reason for this inclination is that the wiring
harness has reached its upper boundaries to accommodate ECUs as
cars incorporate nearly 100 ECUs nowadays. This results in a broad
spectrum of digital and electronic attack surface available where
contact is present with various built-in systems along with numerous
widely ranging external networks such as Wi-Fi and cellular networks.
A collaborative effort between the supply chain and the
comprehensive ecosystem along with a holistic approach is required
where their involvement and contribution matters highly to attain
security in the complex systems specified above. To attain effective
security, it is very important to deal with the components and threats
along with the attack points as a whole entity instead of considering
them individually. In the context of security, both physical and the cyber
worlds should be considered to be compromising as any one of them
may lead to devastating results collectively to a vehicle’s systems. The
surfaces prone to attack due to exposure and hacking on a next-
generation car are illustrated in Fig. 8.

Fig. 8 Surfaces prone to attack due to exposure and hacking on a next-generation car

Layers of Security
The three layers that constitute the security in an automobile are,
namely, hardware security, network security, and software security.
Hardware Security
The hardware security systems offer physical protection in a car such
as the firewall to the engine, seat belts, and airbags. They offer
protection to the operating components in case of accidental or
intentional damage. Various building blocks of hardware security are
used in wide ranges to secure the ECUs and the buses. A few of these
hardware security features are described here.

Secure Boot Along with Software Attestation Product keys and

digital signatures are checked, thereby detecting tampering if any in the
boot loaders as well as critical operating system files. The invalid or
tampered files are blocked from execution, providing a trusted
foundation on operating ECU, much before it gets infected from
tampered files.

Trusted Execution Module A unique identifier is created for each

approved component by using cryptographic techniques. This enables
an accurate comparison between the known authorized source and a
new startup environment. Any attempt made by unknown or
unauthorized component or source is prevented as the launch of code
is arrested when the match is not found.

Protection from Tampering The user data such as account

credentials and intellectual property along with encryption keys are
encrypted at compile time. Decryption is performed during a small
execution window; thus protection of information is ensured from
attempts of tampering and reverse engineering.

Cryptographic Performance Acceleration Cryptographic

performance is improved by utilization of optimized hardware for
encryption workloads. This ensures easier incorporation of public key
or symmetric encryption into various applications and processes. The
hardware is designed specifically to enhance and improve the
computationally intensive operations involved in encryption.

Protection of Active Memory Instances of buffer overflow need to

be prevented as malicious code may exploit them. This is accomplished
by embedding the functionality of pointer checking in the hardware;
thus vulnerabilities in the code are reduced.

Unique Device Identity Unique identity of each and every device is

known to the manufacturers, and it enables secure identification. It
prevents unapproved devices from accessing the network and systems
intended for a particular manufacturer.

The following sections describe the instances where the hardware

security is realized real-time in an automobile.

Smart Keys
Smart keys are electronic entities intended to provide access and
authorization to automobiles. Vehicles provided with smart keys can be
started without insertion of the key in the ignition as long as the
presence of the smart key is ensured within the car. Settings can be
adjusted as per the requirements of the users on locking methods such
as the press of a button on the door handle or the smart key or the
touch on a capacitive area on the door handle. Trunk release is also
automated by smart keys electronically along with buttons inside the
car which can be used to release the trunk mechanically.

Anti-Theft Alarms
Anti-theft alarms are systems that are installed by manufacturers to
prevent unauthorized access of the vehicle. Various systems coupled
with GSM and GPS are available where the users are intimated through
a message regarding the unauthorized access if done, and based on the
cost of the system, the complexity of the system varies. A low-end
system sends a message to the user when an unauthorized attempt to
steal a car is made, whereas a high-end system files a complaint to the
police along with deactivating the fuel injector, thus making the attempt
futile.

Software Security
Only direct physical contact of the hackers with the car made the
automotive networks vulnerable previously. But nowadays time and
money along with unwavering effort from an attacker can yield access
to these systems easily without any physical presence too. Common
protocols are used to link a huge number of ECUs, and this has
potentially amplified the attack surface, and accessibility to vehicles has
also increased. ECUs with diverse competencies are present in a vehicle
[7]. This increases the difficulty to add hardware security capabilities to
some of these ECUs; hence software-based security along with
cooperating processors are required. Some of these features that
defend the vehicle are described below.

Secure Booting Secure booting cooperates with the hardware and

makes sure that the software components that are loaded are valid.
This validity ensures for the rest of the system that there exists a root of
trust.

Partitioned Operating Systems This involves a general combination

of hardware and software intended for isolation of various processes or
functions, such as those on the extreme background rather than those
that are vital for the vehicle to run in that instant. Hence, the
complexity involved in associating multiple systems onto a single ECU
is thus decreased. Various techniques such as containers and
virtualization aid in assistance for update or replacement of individual
functions, preventing any impact on the overall operation [8].

Authentication Authentication provided by just a smart key is no

longer enough in this era where never ending advancements in
technology are present. Authorization of electronic keys, passwords,
and biometrics should be mandatory to access personal information
stored in the software of a vehicle as a profile. In the same fashion,
authentication by several ECUs is required in order to prevent an
attacker gaining control of the system by sending messages or faulty
commands.

Imposition of Appropriate Behavior Cyberattacks usually involve

compromising one component in a system and using it as a leverage to
compromise the rest of the system. Prevention of such an activity in a
network is vital for detection and correction of various threats of
malicious nature. These are enormously useful and can be utilized in a
connected car environment with a collection of cars in the vicinity.
Tampering or hacking into one of the cars in the vicinity may pave a
way for a cumulative attack by using the affected car as a trusted source
for other cars, and this is efficiently evaded.

Advanced Keyless Entry

Advanced keyless entry means that the key or the smart key need not
be pressed to unlock or start the car. Just the presence of the key within
the required vicinity of the car is enough to unlock the car. The locking
and unlocking methods may differ for different vehicles [9].

Network Security
In-vehicle networks contain a combination of operational and
personally recognizable information. This may involve navigation
routes, current location, call history, etc. It is vital to establish
operational security, privacy, and consumer trust, and this is attained
by protection of data and messages over the communication bus.
Various common protocols such as controller area network (CAN),
media-oriented systems transport (MOST), local interconnect network
(LIN), automotive Ethernet, FlexRay, Bluetooth, Wi-Fi, and mobile 5G
make it possible to protect and safeguard the network since good
security techniques that are well tested over the time exist in them. But
when new protocols are considered such as dedicated short-range
communications (DSRC), they generally magnify the threats, thus
intensifying the attack vectors. Security-enhanced ECUs may be
coupled with security-enhanced networking protocols, thus ensuring
enhanced authenticity, reliability, and integrity of the transmitted data.
Without significant hindrance in performance, latency, or real-time
response, the following features ensure secure networks [10].

Authentication of the Device and Messages Communications are

verified such that they arrive from an approved source. Protection of
the authentications is attained so that it is not spoofed or recorded or
replayed.
Access Controls Pre-approval of systems and sensors is done, and
communications between only the above two are allowed, and the rest
of the unapproved messages are blocked along with the alerting
regarding any invalid attempts to the security systems. Different access
rights are provided to various parties such as manufacturers, end users,
drivers, and law enforcement officials to the information systems of the
car that have to be authorized and accordingly controlled.

Vehicle Tracking Systems

Vehicle tracking systems are intended to collect the automatic vehicle
location of various vehicles and project this massive data into a
comprehensive visual representation. This information is used by
manufacturers where in case of an accident assistance is provided in
some instances. Various popular uses of vehicle tracking systems are
theft prevention, stolen vehicle recovery, tracking assets during
transportation, fuel monitoring, etc.

Remote Control and Access

In the era of connected vehicles, remote control and access plays a
significant role for various tasks like service through remote access,
driverless cars controlled from remote operation centers, etc. Latency
and system outages are a few hindrances that prevent the remote
control and access to be utilized to their full potential in automotive
systems. With the advancement of technology with each passing day,
these bottlenecks are miniscule. Thus the remote control has various
energy and environmental impacts where drive cycle is optimized
which in turn improves the fuel economy.

Summary
The various vehicular safety features prevalent in the automobiles to
enhance the safety as well as security are explained here. The
escalating growth in the field of vehicular safety is motivated by a
combination of dynamic entities. In the era of connected vehicles,
connectivity of the vehicles with the external world is essential. Due to
this the attack surface is extremely widened leading to vulnerabilities.
Compromising connectivity to address the vulnerabilities is not a
solution; thus, advanced safety and security measures should be
embedded in the vehicles. The vehicles should be well equipped to
handle such attacks once in a while, and such sophisticated safety and
security maneuvers are considered mandatory by the automakers
nowadays.

References
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B. Deng, X. Zhang, Car networking application in vehicle safety, in 2014 IEEE
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2014.​6976402
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C. Li, J. Wang, H. Li, X. Liu, Y. Wang, Intelligent control system of automobile
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Automotive Security Best Practices. Recommendations for security and privacy
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© Springer Nature Switzerland AG 2021
M. Kathiresh, R. Neelaveni (eds.), Automotive Embedded Systems, EAI/Springer
Innovations in Communication and Computing
https://doi.org/10.1007/978-3-030-59897-6_2

Virtualizing an Automotive State-of-the-

Art Microcontroller: Techniques and Its
Evaluation
Arun Kumar Sundar Rajan1 and M. Nirmala Devi1
(1) Department of Electronics and Communication Engineering,
Amrita School of Engineering, Amrita Vishwa Vidyapeetham,
Coimbatore, India

Arun Kumar Sundar Rajan (Corresponding author)

Email: s_arunkumar@cb.amrita.edu

M. Nirmala Devi
Email: m_nirmala@cb.amrita.edu

Keywords Hypervisor – Hard real-time systems – Automotive

electronic control units – Multicore processors – Virtualization

Introduction
Cars are no longer just vehicles of transportation but a complex and
innovative electronic entity which ensures our safety and has become
an integral part of our day to day life. Over the last two decades,
technological innovations in the automotive domain started replacing
the traditional mechanical components with more and more electrical
and electronic devices. Luxury cars like BMW 7 series have more than
150 electronic control units (ECUs) [1]. Though these devices facilitate
modularity in operation, it increases the cost of deployment and
maintenance. Original equipment manufacturers (OEMs) have taken an
approach of restructuring the E/E architectural components into
specific domains or zones [2], with a future focus of achieving a
centralized computing platform (CCP) [3]. Consolidation of small
applications like acoustic vehicle alerting system (AVAS), ventilation
system (HVAC), and charge control unit (CCU) into the zone of vehicle
control unit (VCU) is an example of such restructuring process.
For quite some years, hypervisor (HV) had been a known solution
for consolidating real-time heterogeneous applications onto the same
hardware and at the same time ensuring isolation of temporal, spatial,
and faults among the applications. When a system is virtualized, it is
possible to plug and play an application without interfering other
existing applications [4]. Efficiency and performance of the hypervisor
primarily depends on how the underlying hardware can support for
virtualization.
Advanced processors with built-in virtualization features are used
in automotive domain for zones like infotainment, but not yet deployed
in safety critical zones like powertrain and vehicle control functions.
Compared to controller chips [5], processors generally do not own the
data they process nor control, and they depend on the reliability of
external memory and its data transfer. This brings an uncertainty on
the safety and security aspect! Additionally, execution of ASIL-D [6]
powertrain functions must be monitored and verified by the hardware
—where MCUs with lockstep core functionality suffice this requirement.
In view of safety and security standards, automotive original
equipment manufacturers (OEMs) still insist on pursuing the
powertrain functionality development on multicore controller
platform (MCU) instead of advanced many-core processors. Although
automotive MCUs have many cores and execute at higher clock speeds,
the common problem is that these MCUs do not facilitate hardware-
assisted extensions for virtualization. Furthermore, hardware resources
and response time of MCUs are still a bottleneck compared to that of a
personal computer (PC). It is also critical in a virtualized system to
share the MCU’s hardware resources like memory, peripherals, and
system clock among the applications or virtual machines (VMs).
In this chapter, the following techniques for virtualizing a legacy
system are discussed:
 Securing a virtual machine
Synchronizing the start-up of a virtualized system
Handling of hardware interrupts and traps
Facilitating peripheral access (input/output access) to the
applications
A demonstrator with two heterogeneous virtual machines, namely,
application for governing the engine control unit (E-ECU) and vehicle
control unit (VCU), was used. These applications were ported to a real-
time automotive powertrain controller (TC29x-AURIX) [7], and a
prototype version of the hypervisor from ETAS GmbH [8] was used.
Detailed findings from our demonstrator are presented in the reference
[9]. Experimental observations from the demonstrator are put forth,
followed by recommendations and limitations of the virtualized system.

Hypervisor Classification
Hypervisor , also termed as virtual machine monitor (VMM), is a
software technique to consolidate multiple virtual machines (VM) or
applications on the same hardware. A common example, most of the
users would have Windows OS installed on their laptop. Now, if the user
wanted to use the same laptop to work with LINUX OS—there are two
options:
To uninstall windows and install LINUX
Inside the Windows environment, the user shall install an application
called “VMware,” and install LINUX inside the VMware
The former option restricts the user from accessing applications in
Windows. However, the latter supports the user to access applications
of windows and LINUX simultaneously on the same laptop. Here,
VMware plays the role of hypervisor/VMM, enabling applications
running on Windows and Linux to use the same, underlying the laptop’s
memory, peripheral devices, etc.
Having the context of hypervisor set, the next step is to classify
based on the deployment [10, 11] of hypervisor.

Type 1 or Baremetal Hypervisor

Hypervisor is a software layer that executes directly on the hardware,
encapsulating all the access towards the hardware. The operating
system (OS) is part of the application, referred as guest OS. Applications
along with their OS work like a plug-and-play components, as shown in
Fig. 1a. The hypervisor layer forwards the hardware interrupts to the
application and also serves the request for hardware access.

Fig. 1 Overview of type 1 and type 2 hypervisor

Type 2 or Hosted Hypervisor

In contrast to the type 1 hypervisor , the hardware comes with an OS
(host OS), and the hypervisor is implemented on top of the host OS. In
this type, the hypervisor cannot directly access the hardware and
instead use the services provided by the host OS, as shown in Fig. 1b.
The applications can also have their own OS (guest OS). Compatibility
between host OS and hypervisor is a decisive point for the design.
It has been over several decades since the hypervisor has found its
use in servers deployed at data centers. A brief history on the journey
of virtualization is presented in works of Strobl et al. [12]. An
embedded environment is a miniature of PC environment, designed for
a specific purpose with limited hardware resources but robust. Real-
time embedded systems have always been hindered from virtualization,
because of hard real-time deadlines and limited resources to share [13,
14]. With introduction of fast multicore embedded chips [15],
virtualization seems to be a possible attempt [12]. There are different
types of embedded hypervisors, commercial as well as open source. A
detailed comparison of four known embedded hypervisors is presented
in our previous work [9].

Implementation
In the automotive domain, the target is not just to execute an
application but to ensure they are executed in hard real-time and fail-
safe. Considering the safety and security standards that are to be
fulfilled, automotive original equipment manufacturers (OEMs) pursue
the powertrain functional development on multicore controller
platform (MCU) instead of advanced many-core processors. Compared
to controller chips, processors generally do not own the data they
process, and they depend on the reliability of external memory and its
data transfer.

Step 1. Know About Your Hardware

Some of the known automotive state-of-the-art MCUs are as follows:
Hercules TMS570—ARM Cortex-R4 architecture [16]
Infineon’s AURIX—TriCore architecture [17]
Freescale’s MPC5643L MCU—Power architecture [18]
Renesas’ H50/P1x MCU [19]
STMicroelectronics’ SPC5 MCU—Power architecture [20]
The level of safety and security aspects is one step ahead in these
devices, as they ensure at the hardware level if the executed instruction
is correctly handled or not (lockstep cores). A common downside is that
these MCUs do not possess the instruction set architecture (ISA) [21] to
support virtualization. For controllers lacking hypervisor mode, a
different strategy is required to implement virtualization. In this
section, details about virtualizing such a MCU (AURIX TC29x) are
elaborated.
Infineon’s AURIX family TC29x microcontroller is an automotive
state-of-the-art multicore controller, with three independent 32-bit
TriCore™ CPUs (also termed as core). A block diagram of the AURIX
TC29x controller is shown in Fig. 2 [9]. A user guide and details of
microcontroller are available in the reference webpage [22].

Fig. 2 Block diagram of AURIX TC29x controller [9]

An important strategy for virtualizing a hardware is to know about
the modes of access control over its memory and peripheral regions.
MCUs with hypervisor-assisted extensions possess a separate operating
mode with limited access to the hardware. In the case of AURIX TC29x
controller , there is no hypervisor mode. It has a memory protection
unit (MPU) and three standard operating modes, namely, user-0, user-
1, and supervisor mode [22]:
User-0 Mode: This mode does not allow access to any peripheral
devices. Enabling or disabling of interrupts is also not permitted.
User-1 Mode: This mode allows access to unprotected peripherals
like read/write access to serial port, read access to timer, and I/O status
registers. It also allows disabling interrupts for a shorter period, which
can be overridden by system control register.
Supervisor Mode: This mode permits read/write access to system
registers and all peripheral devices. It also allows enabling and
disabling of interrupts.
 From the hypervisor perspective, applications run independently.
These applications will approach hypervisor for hardware accesses and
to communicate with other applications. The strategy for MCUs without
hypervisor extension is to exploit a combination of MPU and existing
standard operating modes. Based on privileges of the operating modes,
applications are made to execute in a lesser privileged user-1 mode, and
only hypervisor executes in supervisor mode.

Step 2. Securing the Partitioned Memory Region

The next step is to distribute the heterogeneous applications onto the
hardware. Consider a scenario of three heterogeneous applications,
with each application distributed to a core of TC29x controller. The
same is depicted in Fig. 3. Thus, the entire device is divided into three
virtual partitions. Note: There are some commercial hypervisors which
are capable of handling multiple VMs on the same core.

Fig. 3 Distribution of applications in a multicore device

The memory and peripheral address region for each partition is

governed using MPU. MPU also monitors the access of an application
(read, write, and execute). MPU understands the regions to be
protected by using its base/limit register pairs, which hold the access
type and memory address range details. Each MPU base/limit register
pair has to be configured statically. Violation of access to the protected
memory region will end up in a trap. For a nonintrusive
implementation of a virtualized system, the entire address range in
terms of flash, RAM, and peripheral address space is recommended to
be protected using MPU.
In additional to MPU configuration, there are few basic
configurations needed for each partition. These configurations are done
based on the application, and this information is needed for the
hypervisor.
(a) Configuration of interrupt handlers and their priority

(b) Configuration of exception/trap handlers

Step 3. Setting Up of the Start-Up Sequence

In a multicore controller , during power-on (or reset), only one core
will begin its execution. This core performs boot-up sequence of the
controller. A simple explanation of the boot-up sequence can be seen in
Jacob’s blog [23]. Once the checks are complete, the control is handed
over to the entry point (_main) of the application. This entry point will
commence the start-up sequence of other cores, as depicted in Fig. 4.
The start-up sequence will perform initialization and then transfer the
control to the operating system of the corresponding application.
Fig. 4 Start-up sequence of a conventional multicore system
The hypervisor should know the number of cores that it will handle,
and the hypervisor plays the role of starting other cores. Figure 5
depicts the start-up sequence in a virtualized environment. Hypervisor
starts the cores at supervisor mode , and after the initialization, the
hypervisor switches the execution to user-1 mode before handling over
the control to OS.
Another random document with
no related content on Scribd:
Choin were provided with torches which they lighted now with
difficulty in the rising wind, and by their flaring light Péron saw the
rude stone figure over the door which gave the house its name; but
its appearance was so forbidding that he remained, for a few
moments, motionless in his saddle. It seemed a poor place at which
to invite a delicately reared young woman to dismount on a cold and
gloomy night, and for such a cause.
 CHAPTER XV
THE SIGNAL

CHOIN had been too well instructed by Péron to express any

surprise at finding the door of the tall house unfastened, and he and
one of his men entered, and lighted some tapers they had brought
with them, in two of the lower rooms. But before he assisted
mademoiselle to dismount, Péron went into the house also, and
finding his way to the stairs, began the ascent; he could not be
satisfied until he knew whether Richelieu’s men were there or not.
On this point, however, he was soon reassured, for he had scarcely
taken three steps up before he was softly challenged, and giving the
cardinal’s watchword, received the reply. He found five of
monsignor’s picked men sitting cross-legged on the floor, around a
rushlight, playing cards with perfect nonchalance. The tightly
shuttered windows hid this faint illumination from the outside, and the
soldiers played piquet in such absolute silence that their presence
was not easily detected even by any one on the lower floor. Péron
only stayed long enough to exchange a few words with the leader, a
quiet man of middle age, who understood his business. Neither he
nor Péron had any distinct idea of how large a party might be
expected to follow the appearance of Mademoiselle de Nançay; but
the advantage was with those in the house, and it seemed that they
might be equal to twice their numbers. After a brief exchange of
views on the best means of securing a large body of prisoners,
Péron quietly descended the stairs once more and went out to assist
mademoiselle to dismount. But he found that she and her woman
were already standing on the step, a broad, flat stone at the
entrance, and she was in no very good humor at being compelled to
wait in the cold. He apologized for the delay and invited her to enter
the room at the rear, a small one, which he had selected as being
near enough to the stairs for him to be able to get her to a place of
safety in the event of a fight. But he forgot her wayward temper; she
would have none of the back room.
“I should die here!” she announced, shivering at the chill and the
bleak aspect of the place, for the house was only partially furnished,
and that with the plainest of furniture; “I will go into the front room;
there I can have a fire, and at least two tapers.”
“But, mademoiselle,” remonstrated Péron, “I chose this room for
serious reasons. I—”
“But, monsieur,” she retorted tartly, “I choose the other for serious
reasons. Sirrah, get some fagots and build me a fire,” she added
sharply, addressing one of Choin’s troopers who was lounging on a
settle in the larger room, which she had now entered.
The man roused himself at her words, and stumbled awkwardly to
his feet, but he looked to Péron for orders. Mademoiselle de Nançay
stamped her foot on the floor.
“I tell you I will have a fire,” she said angrily.
Choin had entered as she spoke, and her peremptory manner
angered the maître d’armes.
“Mademoiselle shall have a fire if our leader orders it; otherwise not,”
he said bluntly.
Renée stared at the stout Italian, her great eyes flashing in the
loopholes of her mask, but she was quick to recognize honest
courage even of the lower sort, and in her heart she forgave Choin
for his brusque manner. But before there was a clash between the
two, Péron interfered and ordered the soldier to build a fire if he
could find fuel enough in the house. Fortunately there was a small
supply, the place having been recently occupied, and mademoiselle
sat down, still cloaked and masked, to watch the building of the fire,
while Péron sent the horses away in the charge of another trooper to
the stables of the Golden Pigeon, to be fed and watered that they
might be in condition for future use. He then gave his thoughts to the
disposition of his men; Choin he posted at the rear entrance to the
house, which he had reconnoitered and found opened into a
deserted garden surrounded by a low wall. For the time being he
allowed the other men to rest in the room which mademoiselle had
refused to occupy, and for himself retained the place at the front
door, which he believed to be the point of danger. There was a small
grille in the upper half of this door, and through this he could dimly
see the black outline of the houses across the lane, and above, the
far-off glimmer of the stars. It was too dark to see twenty yards away,
and the night was very still though it was not yet eight o’clock. The
man in command above stairs had told him that the cardinal’s orders
were that all shutters should remain tightly closed and no light be
shown. This being the case, Péron could not divine how
mademoiselle’s presence in the house could be discovered or serve
as a decoy for the conspirators. He was sorry that on this point he
had not asked for more precise instructions, but remembered that
she was not to appear at the window, and he could only suppose
that their spies had seen her arrival and would report it. But even on
this head he was not satisfied; he thought of her determination to
pass in full view of the Golden Pigeon, and he did not know what
significance might be attached to that, or if it had any beyond the
wilfulness of a spoiled beauty. He had, too, a quick sympathy for her
in her unpleasant situation,—her father in the hands of his worst
enemy, and she compelled to play the rôle of a traitress to her own
party. He could understand and even pardon the bitterness of her
mood when he remembered all that she had to undergo. What to do
with her, and how to protect her, was a problem which troubled him
much; for to try to control her motions was like trying to handle a
thistle. He had every expectation of a sharp affray, and it was hardly
probable that any number of desperate men would allow themselves
to be entrapped without much bloodshed, and he did not know how
near or dear some of them might be to Renée de Nançay. What she
would do under such circumstances was a perplexing problem.
Unless he used force, he could scarcely hope to keep her out of the
reach of danger. He had no personal anxieties about the result of the
struggle, but what should he do with mademoiselle? Her woman,
too, he regarded as mischievous, and she belonged to that heroic
build of womanhood which can strike as stiff a blow as most men
and better than some. Her stubborn loyalty to her mistress
recommended her to him, but he recognized an additional danger in
the fire of her fierce black eyes. That she was equal to stabbing one
or more of his men in the back while they were engaged with her
friends in front, he did not doubt. Yet to lock Ninon and her mistress
in a room overhead was a measure which he could not view with
favor. He had had no previous dealings with women, and he had a
profound dislike of using strong measures toward the weaker sex.
While he was revolving all these matters in his mind, the man who
had taken the horses to the Golden Pigeon returned and reported
that all seemed quiet enough, though he had observed a number of
men gathered in the courtyard of the inn, and he had noticed that all
wore knots of pale blue ribbon somewhere about them, either on hat
or cloak or sword hilt. But for the rest there was nothing remarkable,
and they apparently took no heed of him, although he had noticed
two knaves stealing into the stable to stare at his horses. For the
moment Péron was uneasy with the thought that these might be
stolen, but reflected that the landlord of the Golden Pigeon was too
prudent a man to take any risk of having to make good the loss of
seven horses with their equipments.
Having disposed his sentinels to his satisfaction, Péron went to see if
all was well with his involuntary guests. He had no doubt of the
meaning of the pale blue ribbons now, and grew more alert and in
better spirits as the danger approached. He was a born fighter, and
but for the responsibility of mademoiselle’s presence, would have
enjoyed the prospect of a sharp skirmish; an adventure without peril
was never to his taste.
He found the two women alone in the room, where the fire was still
smoking, having been kindled with partially green wood. There was a
plain oaken settle in the room, and two or three stiff chairs; there was
no rug on the floor, but it was partly covered with rushes. It was a
bare enough place; and he noticed that they had extinguished one of
the tapers, leaving the other burning in a niche on the wall. Ninon
lay, half reclining, on the settle, her cloak rolled up into a pillow under
her head, while mademoiselle sat bolt upright in one of the chairs by
the fire, staring angrily into the flames. She had laid aside cloak and
mask and was revealed in her simple gray gown, her hair disordered
by the ride, lying in loose curls on her shoulders. She had a brilliant
color in her cheeks, and her eyes sparkled with anger; yet she
looked unusually beautiful, the very picture of a wilful, spoiled child of
fortune. Péron, standing at the door, bowed to her gravely and asked
if he could do anything more to make her comfortable.
“Ay, sir,” she said haughtily; “send for my horse and let me go on to
the Château de Nançay.”
“I would gladly, but for my orders, mademoiselle,” he replied, with
truth.
She shrugged her shoulders. “I am tired of your orders, M. de
Calvisson,” she remarked. “If I were a man, I would take orders from
no one but my own conscience.”
“Mademoiselle, if you owed monsignor as much as I do,” he replied
dryly, “you would serve him from love and not from fear.”
She elevated her eyebrows with an air of incredulity.
“Ciel!” she exclaimed; “is it possible that you love Cardinal de
Richelieu?”
“I should be an ingrate if I did not,” he retorted boldly. “It is always
possible, mademoiselle, for a statesman to make enemies; M. le
Cardinal has made many, but had he no other friend, I would be one
still.”
She smiled scornfully. “I admire your devotion, monsieur,” she said;
“it is doubtless worth the hire.”
“Mademoiselle,” Péron exclaimed hoarsely, “you take advantage of
your sex!”
“You forget, M. de Calvisson,” she replied, “that a prisoner has no
resource but her tongue. However, I beg your pardon, I spoke in
anger.”
He bowed gravely, too deeply incensed to reply, and remembering
the cardinal’s instructions about the shutters, he walked across the
room toward the nearest of the two windows and began to make the
fastenings more secure. As he did so, mademoiselle rose
deliberately, and taking the taper in her hand, walked to the other
window.
“Is this also secure, monsieur?” she asked, in a tone of propitiation.
“’Tis well to fasten the bolts, for we two women need a little
undisturbed rest.”
As she spoke she laid her hand on the bolt, and Péron, deceived by
her manner, turned to examine that shutter with no unusual haste.
So it happened that before he suspected her intention, she had flung
open the blind, and in an instant tossed the burning taper out into the
darkness of the night. He sprang forward and fastened the shutter in
a moment, but he fancied that the mischief was already done, for
she stood laughing and looking at him with shining eyes, the same
look of triumph on her face that it had worn on the day when she
burned the papers. What manner of signal it was, though, he was at
loss to divine, but he saw that he must watch her as closely as a cat
watches a mouse, or she would defeat every plan of the cardinal’s
as easily as she routed him at every point. But he had no wish to
subject himself to the sharp cuts of her tongue, nor did he wish to
intrude on the little privacy she had. Fortunately, he was relieved of
either necessity by seeing a hammer and some nails in the corner by
the door. He called one of the men and briefly directed him to nail up
the shutters as quickly as possible. This was an easy task, and when
it was done, he sent the man away.
“Mademoiselle,” he said gravely, “I regret to take this extreme
measure, but there is no alternative.”
She was again sitting by the fire, and she looked up with a roguish
face.
“I thank you for the greater security, monsieur,” she replied with a
smile. “There is a proverb about fastening the door of a house after
the thieves have gone.”
Péron bowed gravely. “I understand you, mademoiselle,” he replied;
“’tis evident that—in spite of Ruel—I was born a fool.”
With this, he went out and closed the door that the two might be
undisturbed, and resumed his place at the grille, angry and mortified,
but determined to make amends for past blunders by redoubled
vigilance.
 CHAPTER XVI
THE CARDINAL’S SNARE

MORE than an hour had passed in this tedious watch; the stillness
without was scarcely greater than the stillness within. Mademoiselle
and her woman remained in their quarters, and the soldiers waited
indifferently for the outcome. From his post by the front door, Péron
again and again looked out at the grille and tried to search the
darkness with his anxious eyes, but without result; he was becoming
more and more convinced that Mademoiselle de Nançay had in
some manner defeated the cardinal’s plans. But his labor was not to
be as fruitless as he supposed, and Renée was, in one point, to
meet with less success than usual. Just when the situation seemed
least promising, Péron heard Choin coming on tiptoe toward him.
The hall was lighted dimly by a rushlight sitting on the floor, and he
could not see the face of the maître d’armes well enough to discern
his expression. The Italian came close to him before speaking.
“There is some one in the garden,” he whispered; “I heard the sound
of a horse’s hoofs on the road, and now I hear the brush crackling by
the wall on the east side.”
“Good!” ejaculated Péron, with relief; “I am tired of sitting, like a rat in
a trap. How many horses were there?”
He asked this as they walked swiftly to the rear entrance.
“Only one,” replied Choin, “and there was a long pause after he
stopped at the end of the wall.”
They had now reached the door, and Péron opened the grille softly
and looked out. At first he could see nothing in the darkness, but
after a moment he became accustomed to it and was able to discern
the dark outlines of a man coming cautiously toward the door. Péron
signed to Choin to be silent, and both waited in breathless suspense.
After another pause, evidently spent in reconnoitering, the stranger
advanced more carelessly. To the surprise of the watcher within, he
made straight for the door and tapped softly twice and loudly once. It
was undoubtedly a preconcerted signal, and Péron, by signs, told
Choin to withdraw from sight when the door should be opened; then
he answered with the password given him by the cardinal, which
seemed to dispel the visitor’s doubts.
“Open,” he said in a low tone, “’tis I, Gaston; why do you keep me so
long?”
Without replying, Péron flung the door open, standing well in the
shadow behind it as he did so.
But his caution was unnecessary; the stranger pushed in, seemingly
anxious to be within the house. In a moment the bolts slipped behind
him and he was a prisoner, but he had no suspicion, as yet, of the
trap into which he had fallen. He was a man of medium stature,
closely muffled in a dark cloak, the collar turned up about his face
and his plumed hat set low over his forehead. As he entered, Péron’s
quick eye caught the gleam of golden spurs on the heels of his high
leather boots. He carried his sheathed sword in his hand, as if he
were prepared for any misadventure. He took no heed of the way the
door was closed nor of Péron, and advanced to the middle of the hall
before he observed Choin, who had posted himself with his back
against the main entrance. The noise of his arrival had roused the
soldiers in the room to the left, and two of them came to the door and
thrust out their heads to stare at him. Something in the stillness of
the house, in the strange faces of the men, made him stop short and
wheel around to look at Péron; the light was too dim for him to see
plainly, but he was disturbed. This was not the reception that he had
looked for in this place.
“What is this?” he ejaculated in a high, peevish tone, a tone that
Péron seemed to recognize. “Where is M. de Nançay?”
“He has not come,” replied Péron, promptly, “but Mademoiselle de
Nançay is here.”
He spoke at random and by impulse, but he saw that his words had
done much to remove the stranger’s suspicions.
“Pshaw!” he exclaimed, “’tis strange to send only a girl—at such a
time. Where is she?”
“This way, monsieur,” Péron replied, curious to see the result of this
accident, and tempted, too, to confront mademoiselle with her friend.
Ninon opened the door in answer to his summons, and without a
word the stranger thrust past her into the room, cloaked and
bonneted as he was. Péron followed too quickly for Ninon to shut
him out, for he had no mind to leave this new-comer to talk privately
with Renée de Nançay. In spite of her woman’s angry glances, he
closed the door behind him and leaned against it, watching the other
two. He was not prepared, however, for the sequel. When they
entered, mademoiselle was sitting by the fire, with her back toward
them, and she only glanced up carelessly, expecting Péron. At the
sight of the stranger, however, she sprang to her feet, and as he
dropped the edge of his cloak and uncovered his head, she recoiled
with a cry of terror.
“Mon Dieu!” she exclaimed, “why did you come here? I made the
signal to warn them away.”
“Mordieu!” he cried in a tone of consternation. “What is this? I was to
come here alone, I have seen no one else; into what trap have I
fallen?”
“They must have sent a messenger to you,” Renée said, recovering
her composure; “you must have missed him on the road. Mère de
Dieu!” she added with fresh trepidation, “and they will think you in
Paris; and yonder,” she pointed at Péron, “is the cardinal’s
musketeer!”
The stranger turned as she spoke, and, throwing his cloak partly
over his face, made a spring for the door. Péron drew his sword, and
as he did so, Renée shrieked aloud.
“Stop, in heaven’s name!” she cried; “do not touch him, M. de
Calvisson, it is Monsieur!”
Péron dropped the point of his sword, but stood firm.
“You cannot pass, monsieur,” he said. He was doubtful of the truth of
mademoiselle’s assertion, thinking she intended to deceive him; but
at his words the stranger let fall his cloak.
There could be no longer any doubt of his identity; there was the full
eye, the hooked nose, the full round chin of the Bourbons. The
likeness that Gaston d’Orléans bore to the king and to the queen-
mother could not be easily mistaken, even in the plain dress he wore
as a disguise. Péron had seen him many times before and knew him
well; he saluted gravely and stood irresolute; the cardinal’s orders
had not mentioned a prince of the blood, indeed he had told M. de
Nançay that the Duke of Orleans would make his terms with the
king. Had Richelieu been deceived, or had he duped the marquis?
These were perplexing questions, and they flashed in rapid
succession through Péron’s mind, as he stood looking at the flushed
and angry face of the prince. Orleans was not noted either for
courage or fortitude in supreme moments. Finding himself fairly
checkmated, he had but one thought, and that was for his own
safety. He turned and began to upbraid mademoiselle.
“How came you here, girl?” he demanded peevishly. “Has that
precious father of yours turned coward and deserted his friends?”
Renée’s eye flashed. “Monsieur,” she said haughtily, “my father is no
traitor to his allies; he has never betrayed a man who perilled his life
and honor for him!”
The thrust went home; the fate of the unhappy and noble
Montmorency was not yet forgotten, and the prince gnawed his lip in
silence. But mademoiselle was not done.
“My father is now a prisoner,” she said, “in the hands of that man
who is alike pitiless and supreme, and I was sent here at the king’s
orders to decoy your friends to this house. I tried to prevent it—I
made the signal, and indeed I am sure that no one else will come;
but monsignor has certainly made one successful cast of his net to-
night;” and she smiled scornfully, as she looked at the handsome,
vacillating face of Gaston d’Orléans.
“Pardieu!” he muttered, “I am lost. The king’s orders! Your father in
the hands of the cardinal, and my mother in Brussels! I am lost! I am
lost!” and he paced up and down the room, wringing his hands like
one possessed. He who never decided anything was suddenly
forced to face an exigency which demanded decision.
It was a strange scene: Péron stood like a statue by the door, his
drawn sword in his hand, and near him Ninon was gazing wide-eyed
at the prince as he paced to and fro. By the fire, Renée stood erect,
her face pale but her eyes aglow with indignation, the most
composed person present.
Presently Monsieur halted in front of Péron.
“Put up your sword,” he said pettishly. “I am a prince of France, and
you dare not oppose me. I shall go out of this house as I came—
alone!”
Péron had been revolving many thoughts in his mind during the brief
time since the discovery of his prisoner’s identity, and he had to
come to a decision.
“It is true that I might risk the king’s displeasure by opposing your
highness,” he said quietly, “but consider for one moment the
situation. I am not in supreme command in this house. There is here
a capitaine de quartier. I heard his voice on the stairs a moment
since, and the place is full of soldiers. If you step out into that hall—if
you attempt to go away—they will seize you, and it will be a public
matter in five minutes.”
“But, mon Dieu!” cried the prince, in a faint voice, “what can I do? My
brother will never forgive me. The cardinal will ruin me! They will
know I am here, if I stay! Where is the advantage?”
“If your highness will think a moment, you will see,” Péron answered
more calmly, as he saw the other’s absolute impotence in the face of
a crisis. “If you remain quiet, no one need know your identity but
Mademoiselle de Nançay and myself.”
Gaston peered at him eagerly; his face had grown pinched and not
unlike the king’s when Louis was suffering from one of his seasons
of ill health.
“How can I trust you, man?” he moaned fretfully. “I can trust no one;
every one betrays me and every one suspects me, even my own
brother!”
“Because you betray every one,” was on Péron’s lip; but he
restrained himself, though, looking beyond Monsieur’s cowering
figure, he saw the contempt and hatred on mademoiselle’s proud
young face.
“You may trust me, your highness,” Péron replied quietly. “I pledge
my honor that no man shall know you if you will stay in the room
across the hall until daybreak, and then ride with me to Paris.”
Monsieur’s face, already white, turned the color of ashes.
“To Paris!” he cried, collapsing into a chair. “To monsignor?”
“To monsignor, your highness,” said Péron, grimly. “My orders are
absolute.”
The prince covered his face with his hands, and there was a moment
of silence. In it Renée’s eyes met the young soldier’s with a
sympathetic flash of contempt for the crouching heap in the chair.
Monsieur’s thick curls fell disordered around his face, and his white
hands trembled as he held them over his eyes. Suddenly he rallied
and sat up, looking defiantly at Péron.
“You can prove nothing against me, sir musketeer,” he said. “I came
here, it is true—but how do you know my errand?”
“It is true that I do not know it, your highness,” he replied gravely,
“neither do the men without know you; there is your advantage.”
“Tush!” said Gaston, with rising courage, “’tis all a trap of Richelieu’s;
a clear evidence of his persecution of me. My brother shall know it!”
He rose from his chair and felt in his pockets for a comb, which he
found, and began to arrange his curls.
“Your pardon, mademoiselle,” he said peevishly. “I could not see for
my disordered hair.” Then he turned to Péron. “Now, sir,” he added,
“I will go to your prison until daybreak, but you shall all suffer for
this!”
Péron laid his hand on the latch.
“I pray your highness to assume your disguise,” he said; “we must
cross the hall, and it is now full of soldiers.”
The prince resumed his cloak and hat with some muttered
imprecations, but he was careful to muffle his face before the door
was opened. As Péron had said, the entry was full of troopers, but at
a sign from him they all fell back and allowed the prince to cross the
hall to a room on the other side, which his captor took care should be
secure before he left him there to rest for the few hours that
remained before daybreak.
Meanwhile Péron found enough to do to make his arrangements and
keep his pledge to the Duke of Orleans. However, the others were
tolerably satisfied with the ease with which they had secured the
prisoner, and did not press the question of his identity, after their
leader told them that he was not at liberty to reveal it. Whatever their
suspicions were, they did not soar as high as the truth, and Péron
felt confident that all would go well, if there was no attempt at a
rescue by the other conspirators.
But all the while another matter troubled the mind of the young
soldier. Monsieur was a dangerous prisoner. He had been in
numerous plots against his brother and the cardinal, and in open
rebellion before, and never yet had offended beyond the king’s
forgiveness. What would be the result of carrying such a prize to
Richelieu? It was a question which no man could answer. And
Monsieur had all the spitefulness and ill temper of his mother. More
than this, had the cardinal purposely spread his net for this royal fish,
or had he believed one of d’Orléans’s numerous confessions? The
last was clearly impossible; monsignor knew the prince too well.
Manifestly, the declaration of Monsieur’s reconciliation had been
made to entrap de Nançay; and now the point remained—would the
capture of Gaston be welcomed, or would his captor suffer for it?
Péron found it impossible to decide, and set about his duty with a
heavy heart; it seemed that this fish might be large enough to break
the meshes of his net or drag him into the deep sea.
 CHAPTER XVII
MONSIEUR AND MONSIGNOR

BEFORE daybreak, Péron was forced to provide a meal for

Monsieur, who, finding himself in an uncomfortable situation, was
disposed to be as peevish and refractory as possible. Without a
single trait of his great father, Henri Quatre, Gaston de Bourbon,
Duke of Anjou and of Orleans, inherited all the deceit, the petty
ambition, and the vindictiveness of his mother, Marie de’ Medici,
lacking however her tenacity of purpose. While the Thirteenth Louis
inherited the sternness of the great Henri, the younger brother was
as unstable as water. Shut up, against his will, in the house at
Poissy, and knowing himself to be once more in the clutches of the
cardinal, whose distrust of him was only equalled by his contempt,
Monsieur had but one thought, and that was of the safest way to
desert his fellow-conspirators.
He demanded food and wine to keep up his failing spirits, and when
both were brought from the Golden Pigeon, he ate voraciously and
drank deeply, gaining in courage at every potation. He had no fear of
the king, his brother, Louis had always forgiven him, although it was
with the indifference of disdain; but of Richelieu he had a wholesome
dread, and he knew that monsignor, despising and suspecting him,
knowing him to have been many times guilty, desired above all else
to cut him off from the line of succession. The more wine he drank
the more determined he became to extricate himself from this
difficulty, as he had extricated himself from many others. To a man
who had but little shame, it mattered not how much had been
revealed by M. de Nançay or by others. Monsieur seldom stopped
for a lie, and never for a prevarication.
When they set out on their ride to Paris, he was in a humor to betray
his best friends, and he showed it by a peevish lack of courtesy
toward Mademoiselle de Nançay. He would not approach her, but
insisted on riding at the head of the party, kept under guard by
Péron, however, who was continually afraid he would try to give
them the slip. The prince had been provided with a mask, and,
muffled in his cloak, was not recognized by any of the party except
the captain of the guard sent by the cardinal. This man had ridden
behind Monsieur but a little way when he leaned over and spoke in a
whisper to Péron.
“Pardieu!” he said with a grimace, “I see what bird we have caught.
He took but one trait of his father, and that is his seat in the saddle;
he rides like a Béarnese.”
Péron made a sign to him to keep silence, and the little troop moved
on; mademoiselle and her woman in the center, and Choin
commanding the men in the rear, for they were not without
anticipation of a skirmish in the forest between Poissy and St.
Germain-en-Laye. They had set out at daybreak from the house of
the Image de Notre Dame, to avoid any attempt at an early rescue of
the Duke of Orleans, and now the sun was just rising over a quiet
landscape. In the east the sky was golden; two great white clouds,
touched with rose and amethyst, floated upward before the sun, as
though the morning spread its wings. The first long shafts of sunlight
made wide avenues of glory through the forest, and there was the
merry twittering of birds in every thicket. Péron felt his spirits rise
with the day; whatever the outcome of his mission, he had steadily
endeavored to do his duty, and he had assuredly accomplished
something of importance. Aware now of how nearly Renée de
Nançay had defeated his plans, he could not suppress a feeling of
curiosity to know how she regarded the turn of events. He cast more
than one searching glance at her erect figure, as she rode in their
midst, but he could make nothing of that mask, and she had not
vouchsafed him a word that morning. He had sent her a breakfast,
but had received no thanks; and when they were preparing to depart,
she had mounted before he could come to her assistance, being
delayed by Monsieur’s peevish assertions of authority. He
remembered the look of contempt she had given the prince, and he
saw that she was as anxious now to avoid Gaston as he was to
avoid her. They made a strange party. Good discipline and a
recognition of the importance of their errand kept the soldiers quiet
and orderly, and the two women were as speechless as mutes; while
a little in advance rode Monsieur, masked and muffled, and as fretful
as a spoiled child caught in a naughty act.
Notwithstanding the anxieties of the leaders, the ride through the
forest was quiet enough, and they entered St. Germain-en-Laye at a
sharp canter, passing through the principal street and out again
without a pause; for in the towns was the greatest risk that the
identity of d’Orléans would be discovered. As the morning advanced,
they began to meet travellers on the highroad, and Monsieur sank
yet deeper into the folds of his cloak and grew more and more
sullen. Once Péron was certain that the prince was recognized. A
party of horsemen rode by, manifestly fresh from court and wearing
the colors of Condé, and more than one of them turned sharply to
stare at the masked rider. However, no one accosted them, and
Péron breathed freer at the end of each league. Their horses were
fresh and covered the ground easily, and it was not long before they
came in sight of Ruel. As they drew near, Péron, who was now at
mademoiselle’s side, addressed her.
“This time we will go through Ruel, Mademoiselle de Nançay,” he
said with a smile.
“As you please,” she answered with a shrug of her shoulders; “this
time I gain nothing and lose nothing by it.”
“Forgive me for having duped you, mademoiselle,” he replied, “and
believe me that I respect such loyalty to your convictions.”
“It is I who should beg your pardon, M. de Calvisson,” she said
frankly; “I said sharp things to you last night, but I recall them. Sir, I
do not blame you for your attachment to the cardinal; he is, at least,
a man. As for that creature yonder,” she threw out her hand with a
gesture of contempt,—“St. Denis! he is not worthy a thought, much
less a drop of an honest man’s blood. That cowardly, treacherous
boy would sell the noblest men of France for the sake of his own
miserable comfort. Heaven forgive me, if I have ever furthered any
cause of his; I can never forgive myself!”
Her vehemence, the earnest tone of her voice, though she spoke so
low, gave Péron a glimpse of another Renée de Nançay,—not the
spoiled, haughty beauty, but an earnest, passionate woman. He
glanced at Monsieur’s unconscious figure and smiled; his own heart
was lighter.
“It is a pity,” he answered, as low spoken as she, “that the brother of
his majesty should be—what he is!”
“’Tis a pity, monsieur,” Renée replied sharply, “that he was ever
born.”
“At least he has served one useful purpose,” Péron said: “he has
shown Mademoiselle de Nançay that he is not worth the trouble that
he has made in this realm.”
“If I were the king,” she retorted, “I would soon end it; I would shut
Monsieur up in the Castle of Vincennes.”
“Ah, mademoiselle, you forget what the life of the king would be,” he
replied; “you forget the tears and intercessions of Madame la Mère.”
“Tears are easier shed than blood,” she said; then added suddenly,
“there is some unusual stir in Ruel; there is the cardinal’s livery.”
They were entering the town, and Péron, looking about for the first
time, saw that, as mademoiselle had said, there was an unusual
commotion. The courtyard of the inn was crowded, and there were,
too, the colors of Richelieu. Monsieur had perceived them and fallen
back, nearer to Renée than he had been the whole morning, and
was evidently uneasy and angry. Péron urged his horse past the
others, and approaching the inn inquired the meaning of the stir.
“The cardinal is here,” was the reply; “he came this morning.”
Further inquiry developed the fact that monsignor had reached his
own house at Ruel some hours earlier and was there then. This was
better fortune than Péron could have expected, and it lifted a load
from his heart. It was easier to get Monsieur to the cardinal’s house
here unnoticed than in Paris, where he was almost certain to be
recognized at once. But it was no easy matter to get the unhappy
prince to see the affair in the same light. To his mind it was no better
to face Richelieu at Ruel than at the Palais Cardinal. Monsieur had
never been able to meet an ordeal, and he was not any better
prepared than usual. At first he refused loudly to move an inch,
holding his horse’s head steadily toward Paris and declaring that he
would see no one, go to no one but the king.
“Your highness may be recognized if you speak so plainly,” Péron
reminded him, “and in that case I cannot answer for the results.”
“Mon Dieu!” cried Gaston, in alarm; “surely, man, they would not hurt
me! My brother would never forgive them if they dared to touch me.”
“Your highness is safe,” Péron replied dryly, “but you would be more
so with the cardinal. He is a wise man and will devise some way out
of this difficulty, I doubt not.”
Monsieur gasped; he was relieved, but he could not make up his
mind. Péron laid his hand on his bridle rein.
“M. le Prince,” he said bluntly, “yonder come some gay gentlemen; if
I mistake not, M. de Bassompierre is among them. If he sees your
highness, this matter will be the talk of the galleries of the Louvre to-
night, the gossip of the Marais, the tattle of the Port Antoine.”
“Parbleu!” ejaculated Monsieur, in a vexed tone, “you are right. Go
on, man, to the cardinal—or to the devil—it must be my unlucky
star!”
Péron did not wait for another change; he gave his orders quickly,
and they all proceeded at a trot to the cardinal’s house. The court
was full of musketeers, and there was a guard at the door; but Péron
was recognized and easily gained admittance for himself, Monsieur,
and the two women. The others remained without, finding friends
and comrades among the guards. Péron sent a message to the
cardinal, and in a few moments received his orders to leave
mademoiselle and her woman in the anteroom below and to come to
him with his prisoner, of whose importance a hint had been
conveyed. An usher led them up the broad stairs, and opened the
door for them to enter the cardinal’s presence. The prince was still
masked and muffled, and walked sullenly into the room, which was a
large one, richly furnished and with a bright fire burning on the