Wealthy socialite Lois Frazer, divorcing her fortune-hunter husband, Howard, finds a gun he's bought. She kills him with it in front of the new man in her life, Lt. Ed Cullen, a homicide detective with the San Francisco police. The twice-married Lois manages to manipulate Cullen into disposing of the murder weapon and moving the body. Cullen ends up investigating the case, assisted by kid brother Andy, who is new to the homicide division and delays his honeymoon to keep working on his first big case.