China Passage is a 1937 American mystery film directed by Edward Killy from a screenplay by Edmund L. Hartmann and J. Robert Bren, based on a story by Taylor Caven. Tommy Baldwin and Joe Dugan are entrusted to carry a fabulous diamond. If they succeed, they will be well paid. If they fail, they will be well buried. When they go to pick up the diamond, there is a great gun battle, a cannister of knock out gas, and the diamond is stolen. The police round up everyone that they can find in the area and search them, but the diamond is not found. Strangely, everyone who was rounded up that night and released boards the steamship Asiatic the next day traveling from Singapore to San Francisco.