Former police detective and alcoholic Max Thursday (Zachary Scott) learns from his ex-wife, Georgia (Faye Emerson), that their son, Jeff, has disappeared with her brother, Fred. Max's investigation leads him to Fred's unsavory associate, Dr. Elder -- but when the doctor is found murdered, Max is arrested. After Georgia provides Max's alibi, Max connects Elder with diamond smuggler Otto Varkas (J. Edward Bromberg), whose moll inadvertently provides a surprising lead to both Fred and Jeff.