Ed Davenport learns that a sandwich he requested to be tested by a lab contains arsenic and blames his wife Myrna. When he confronts her about his suspicions she denies it. He leaves for a business trip and falls ill. Dr. Renault is called to treat him at a motel where Ed Davenport later dies. Before he dies he claims his wife poisoned some candy. After locking the motel room the doctor calls the police. The police arrive to find the corpse missing. The police test the candy and indeed find arsenic. Subsequently Ed Davenport's body is found in a shallow grave. Myrna Davenport is accused of the murder.