Hit man Philip Raven, who's kind to children and cats, kills a blackmailer and is paid off by traitor Willard Gates in "hot" money. Meanwhile, pert entertainer Ellen Graham, girlfriend of police Lieut. Crane (who's after Raven) is enlisted by a Senate committee to help investigate Gates. Raven, seeking Gates for revenge, meets Ellen on the train their relationship gradually evolves from that of killer and potential victim to an uneasy alliance against a common enemy.