Trapped on a planet whose inhabitants are descended from Northwestern American Indians, Kirk loses his memory and is proclaimed a God while the crippled Enterprise races back to the planet before it is destroyed by an asteroid.
As punishment for ignoring their warning and trespassing on their planet, the Melkot condemn Capt. Kirk and his landing party to the losing side of a surreal recreation of the 1881 historic gunfight at the OK Corral.
Kirk beams down to the planet Gideon and appears to find himself trapped on a deserted Enterprise. Spock on the real Enterprise must use his diplomatic skills to deal with the uncooperative inhabitants of Gideon and find the Captain.
After the Enterprise landing party beams down to investigate a geologically interesting planet, their ship is hurled across the galaxy. Kirk and company find a deserted outpost guarded by the deadly image of a beautiful woman.
Kirk, Spock, Abraham Lincoln and Vulcan legend Surak are pitted in battle against notorious villains from history for the purpose of helping a conscious rock creature's understanding of a concept he does not understand, "good vs. evil".