Japanese detective Mr. Moto finds himself hip-deep in international espionage in this adventure tale. In Port Said, a pair of rogues -- French-born Fabian (Ricardo Cortez) and Englishman Norvel (George Sanders) -- are working for a nameless foreign government and devise a scheme to sabotage French ships passing through the Suez Canal. The criminals plan to leave false clues implicating British agents in hopes of sparking a war between the two nations. Mr. Moto (Peter Lorre), posing as a local shopkeeper after faking his own death to avoid suspicion, is assigned to stop them before any lives (or vessels) can be lost. John Carradine and Virginia Field also appear in this, the sixth of eight films that would feature Peter Lorre as Mr. Moto.
by Mark Deming synopsis