In a deliberate throwback to 1940s films noir, a former private eye from that period, Chandler, takes up his old work again, and finds himself constantly driving old cars. He is ostensibly hired by the government to protect a witness, Katherine Creighton, from a gangland leader, John Melchior, who wants to kill her. But Chandler is in fact working for a corrupt government agent, Ross J. Carmady, who is using him as a dupe so that Carmady can murder Melchior and put his own double agent at the top of the racket.

After quitting a position as a security guard, Chandler is offered a job by old friend Bernie Oakman, unaware that Bernie’s been asked by Carmady to find a suitable patsy. Chandler gets his gun back from a pawn shop and follows the French woman Creighton from the moment of her arrival in Los Angeles. He becomes acquainted with her on a train to Monterey, California without revealing that he is tailing her, but soon intervenes when Creighton is assaulted and thrown into the trunk of a car.

Chandler becomes romantically involved with the woman, against his better judgment, repeatedly telling her, “You’ll do.” The two of them end up trapped near an isolated beach, ambushed by Carmady and his associate Kincaid, shooting it out.