Der Hund von Blackwood Castle

In the early days of production, another project entitled "The Angel of Terror" (an original Edgar Wallace novel title) was intended to become the 25th Fflm of the series. The film was to be a West German-British co-production directed by Harald Reinl (it would've been his sixth Wallace film and his first in color). Due to the financial trouble of the British co-producers and scheduling conflicts of Reinl, who was directing Dynamit in grüner Seide (1968) at the time, the project was abandoned.

Referenced in Lukas: Mann und Maus (1998)