Investigating a planet in danger of collision with an asteroid, Kirk, Spock, and McCoy discover Native American inhabitants and a strange alien obelisk. While examining the obelisk, Kirk is accidentally trapped inside and inadvertently triggers a device that gives him amnesia. With time running out, Spock and McCoy are unable to locate the Captain and return to the Enterprise to try and stop the asteroid from hitting the planet. Kirk is found by the natives, who come to believe Kirk is a god. Kirk becomes the tribe's medicine chief and marries the priestess Miramanee.

James Doohan (Lt. Cmdr. Montgomery Scott)
Sabrina Scharf (Miramanee)
Rudy Solari (Salish)
George Takei (Lt. Hikaru Sulu)
Walter Koenig (Ensign Pavel Chekov)
Richard Hale (Chief Goro)
Majel Barrett (Nurse Christine Chapel)
Naomi Pollack (Indian Woman)
John Lindesmith (Engineer)
Peter Virgo Jr. (Lumo)
Lamont Laird (Indian Boy)

• This episode portrays the Native Americans as stereotyped savages, with Kirk the white man seen as a god.