The Enterprise crew investigates the progress made by a planet visited by a Federation ship over 100 years earlier, and find that a book on the Chicago mobs of 1930's Earth has served as the role model for the planet's development.
Air Date: 01/12/68
Director: James Komack
Man, this one has everything. Gangsters, comedy, Fizzbin, Kirk trying to drive a car, and Vic Tayback. If you enjoy the episodes where the crew encounters past Earth-style civilizations, this one should be on your list!