One evening in Los Angeles, police lieutenant Jerry McMullen stops a car driven by lawyer John Morland to tell him that a bank has been held up and a teller killed. The suspect is Red Bailey, a former client of Morland, whom Morland got acquitted on charges of killing a policeman. Farther down the highway, Morland halts at a stop sign and Bailey walks up to the car, gun drawn. Morland gives him a ride and arranges once again to defend him. A few nights later, Morland's burned-out car is found at the bottom of a hill and the driver is so badly injured that he cannot be identified. McMullen thinks this may not have been an accident and, at the Morland home, learns that Morland is supposedly in San Francisco. When Morland's wife Catherine returns from an outing with young district attorney Richard Conroy, McMullen breaks the news of the accident, and she identifies a ring found on the body as her husband's. After McMullen receives confirmation from the coroner that the driver was shot in the chest before the car was set on fire, he goes to see Morland's law partner, James O'Neil, and asks to look over Morland's case files. O'Neil tells him that Catherine probably felt neglected due to her husband's work load. Dr. Pearson, Morland's physician, tells McMullen that he discovered one day that Morland had been seriously poisoned by bug killer found in his kitchen. Morland began to suspect that his wife was trying to kill him when he spilt a bottle of medicine she had brought him, and Toby, their cat, lapped up some of it and died. Pearson tells McMullen that he advised Morland to contact the police but he refused to do so. McMullen and detective sergeant Tom Carey then interrogate Dorothy, the Morlands' maid, who tells them that Morland was jealous of his wife's interest in Conroy. She also mentions that the Morlands maintained a weekend lodge. McMullen and Carey go there and find Conroy, who claims to be doing some investigating on his own. Although Catherine is the police's principal suspect, McMullen soon discovers that a phone call was made to an apartment from the deserted lodge on the day that Morland was killed. McMullen and Carey stake out the apartment and see O'Neil bringing home Marian Gordon, a former girl friend of Red Bailey, who admits that she received a call from him when he was hiding out at the Morland lodge. Although Conroy contends that O'Neil killed his own partner, O'Neil shows McMullen a diary entry in which Morland reveals he found his wife and Conroy embracing and discussed a divorce with her. Later, Catherine denies that this happened but, when McMullen visits her, he finds her about to leave for a trip with Conroy. He shows her a gun which she identifies as hers and tells her that it has just been found near the car wreck and that the bullet that killed the driver came from that gun. McMullen arrests Catherine and Conroy resigns his office. Meanwhile, Bailey has called Marian and goes to her apartment. However, McMullen has had her phone calls recorded and shows up there, finds an armed O'Neil and arrests Bailey. At police headquarters, Marian tells McMullen that O'Neil and Morland had a dispute over money, and McMullen suspects that O'Neil wanted to kill Bailey to get the money from the bank robbery to cover an embezzlement. Bailey admits that Morland hid him at the lodge but says that Morland drew a gun on him, and during an ensuing fight, Bailey knocked him out and left him unconscious in the lodge. After McMullen is forced to release Catherine, O'Neil phones her from the lodge and asks her to come there right away. Dorothy, the maid, has been listening on an extension and tips off McMullen. When Catherine arrives at the lodge, she finds O'Neil dead and is surprised by her husband, who explains that he had hoped to incriminate her in his own death and that the body in the car was actually Willis, the lodge's caretaker. McMullen and Carey arrive and, after a brief gunfight, McMullen shoots Morland. Later, McMullen learns that Morland planted the poison himself to build up a perfect case against his wife.