Episode Title: "SPOCK'S BRAIN"
Production Number: 61
Original Air Date: 09-20-68
Stardates: 5431.4, 4351.5, 5431.6, 5432.3
The U.S.S. Enterprise encounters an alien ship with ion propulsion and unique technology; a humanoid woman appears on the Bridge and incapacitates the entire crew of the Enterprise. When the crew awakens, they find Spock's body with his brain surgically removed. The Enterprise follows the ion trail to the Sigma Draconis star system, and Captain Kirk decides to search the sixth planet, a primitive world in an ice age, with a tribe of large men -- called Morg -- on the surface, and an advanced underground complex inhabited by women -- the Eymorg. Kirk learns that Spock's brain is being used to control the entire complex, and provide for the primitive people living on the planet.
Dr. McCoy uses the ancient alien technology to temporarily gain the knowledge he needs to restore Spock's brain to his body, leaving the primitive Eymorg to live on their own with the male Morg on the surface of the planet.
Factoid: The fourth, fifth, and sixth planets of the Sigma Draconis star system are Class-M and support humanoid societies at various levels of development.
Dr. McCoy: "He was worse than dead."
Guest Characters: Nurse Christine Chapel
Alien Races: *Sigma Draconians
KEY: [brackets]=illusions *star=first appearance