 The Enterprise is investigating a planet visited 100 years ago by the USS Horizon. Kirk, Spock, and McCoy beam down and find themselves in a culture similar to Earth gangs of the 1920 s. They are quickly taken prisoner by men in the employ of a mob boss named Bela Oxmyx. He wishes them to give him phasers in exchange for "a piece of the action", and when they refuse Oxmyx puts them under guard. Kirk creates a diversion with a card game called "fizzbin". Without their equipment, the trio must find a way to unite the planet and escape to the Enterprise.