Philip Raven, a hit man with a soft spot for children and cats, kills a blackmailer and receives payment from traitor Willard Gates in "hot" money. Meanwhile, perky entertainer Ellen Graham, the girlfriend of police Lieutenant Crane (who is after Raven), is enlisted by a Senate committee to help investigate Gates. Raven, seeking revenge on Gates, meets Ellen on the train; their relationship gradually evolves from that of a killer and potential victim to an alliance against a common enemy.