American private detective working in France finds a corpse which promptly disappears, leading to all sorts of trouble with trains.
Excellent little mystery, sort of a precursor to
The Lady Vanishes (also scripted by Launder & Gilliat). This time a body appears on a train, instead of disappearing from one, though a separated train car does serve as a trap for the protagonists in both films.
Lowe and Cummings make a fine team, and the dialogue is sharp. The plot is a bit rushed because of the short screen time, but a wonderful film nonetheless.
Note: All sources say this film was released in the US as Doomed Cargo to avoid confusion with the 1940 John Wayne film, but it's more likely it was released in both the US and UK as Seven Sinners, and the name changed in re-release.