The heirs to a family fortune are required to attend a seance at the spooky old family mansion. However, throughout the night members of the family are being killed off one by one.

On the night express train from Los Angeles to San Francisco everyone’s a suspect when a jewelry magnate is found stabbed to death and an escaped killer is feared on board. It’s up to newspaper reporter Jimmy Hawley (Ben Lyon) to unravel the secrets of the motley group of passengers and find the killer before he strikes again in this tense and atmospheric whodunit.

Mr. Schmidt's costume store is bankrupt because he spends his time on Rube Goldberg-style inventions; the creditors send a young manager who falls for Schmidt's niece Louise, but she'll have none of him. Schmidt's friends Ted, Queenie, and some goofy firemen try to help out; things come to a slapstick head when Louise needs rescuing from a fire.