 In the series debut, individualist private detective Joe Mannix is working at a corporate agency. Company rules dictate only one piece of paper on a desk at a time; Mannix s desk is cluttered. Despite Mannix s disdain for the rules, the head of the agency, Lew Wickersham also knows Mannix "is my best man." Mannix is sent to investigate a missing person s case. The client is a retired mobster, who first tests Mannix. The detective is told the missing person, the mobster s daughter, is kidnapped. Mannix will encounter much treachery before learning the true facts of the case.