Dir: Bernard Vorhaus
Starring: John Mills and Ida Lupino
A chemist investigates a murder that was inadvertently caught on camera
This mystery was based on A Mystery Narrative, a short story by Joseph Jefferson Farjeon. Despite being made quickly and on a low budget, the film has come to be considered as one of the most successful Quota quickies made during the Thirties. Part of the murder investigation leads to a search for clues adjacent to a railway line and there are some good shots of passing Southern Railway 3 SUB EMUs on headcode Bar over H routes. Headcode Bar over H was South Western Division routes Staines-Windsor (attached or detached Waterloo-Weybridge via Richmond), Virginia Water-Chertsey or Weybridge, Waterloo-Chertsey or Weybridge via Richmond and Waterloo-Effingham or Guildford via Cobham. It is the first of these routes depicted as the scenes were filmed close to the Windsor & Eton Riverside terminus in the Black Potts area.