• Production Code: 56
• Stardate: 4385.3
• Original Air Date: Oct 25 68
• Writer: Lee Cronin
• Director: Vincent McEveety
• Guest Stars:
  • Ron Soble (Wyatt Earp)
  • Bonnie Beecher (Sylvia)
  • Charles Maxwell (Virgil Earp)
  • Rex Holman (Morgan Earp)
  • Sam Gilman (Doc Holloway)
  • Charles Seel (Ed)
  • Bill Zuckert (Johnny Behan)
  • Ed McCready (Barber)
  • Abraham Sofaer (Melkotian Voice)

A Melkotian warning buoy is unwittingly destroyed by Kirk and the Enterprise. When Kirk beams down with a landing party, the owners of the buoy, fearing that a pointlessly violent race has entered their space, trap the Enterprise officers in a replica of Tombstone, Arizona (drawn from Kirk's mind) and force Kirk and company to play out the roles of the Clanton Gang - doomed to lose the gunfight at the O.K. Corral at sundown.