The film that Cust watches in Doncaster is Alfred Hitchcock's 1932 film Number 17 (1932). His wife, Alma Reville, was one of the scenario writers.
It is revealed that Captain Hasting's initials are "A.J.M.H."
The first film viewed by Cust with great fascination is Footsteps in the Sand (1939) starring Raymond Massey.
The first of two episodes to feature Nicholas Farrell. Here he plays Donald Fraser, thirteen years later he played Knighton in The Mystery of the Blue Train (2005).
The September 21, 1936 edition of the Daily Mirror features the headline "Did Gareth Jones Know Too Much?" Gareth Jones was a Welsh journalist who revealed the existence of the ongoing Soviet famine to the world in a series of articles in 1933. He was kidnapped and murdered while investigating the Japanese occupation of Inner Mongolia on August 12, 1935. Jones' murder has never been solved but it has been speculated that he was killed by the NKVD, the Soviet secret police.