Star Trek: 1x27
The Alternative Factor
Kirk and Spock encounter an alien named Lazarus who claims to be from an anti-matter universe.
1 - 1The Man Trap Sep. 08, 1966
1 - 2Charlie X Sep. 15, 1966
1 - 3Where No Man Has Gone Before Sep. 22, 1966
1 - 4The Naked Time Sep. 29, 1966
1 - 5The Enemy Within Oct. 06, 1966
1 - 6Mudd's Women Oct. 13, 1966
1 - 7What Are Little Girls Made Of? Oct. 20, 1966
1 - 8Miri Oct. 27, 1966
1 - 9Dagger of the Mind Nov. 03, 1966
1 - 10The Corbomite Maneuver Nov. 10, 1966
1 - 11The Menagerie (1) Nov. 17, 1966
1 - 12The Menagerie (2) Nov. 24, 1966
1 - 13The Conscience of the King Dec. 08, 1966
1 - 14Balance of Terror Dec. 15, 1966
1 - 15Shore Leave Dec. 29, 1966
1 - 16The Galileo Seven Jan. 05, 1967
1 - 17The Squire of Gothos Jan. 12, 1967
1 - 18Arena Jan. 19, 1967
1 - 19Tomorrow Is Yesterday Jan. 26, 1967
1 - 20Court Martial Feb. 02, 1967
1 - 21The Return of the Archons Feb. 09, 1967
1 - 22Space Seed Feb. 16, 1967
1 - 23A Taste of Armageddon Feb. 23, 1967
1 - 24This Side of Paradise Mar. 02, 1967
1 - 25The Devil in the Dark Mar. 09, 1967
1 - 26Errand of Mercy Mar. 23, 1967
1 - 27The Alternative Factor Mar. 30, 1967
1 - 28The City on the Edge of Forever Apr. 06, 1967
1 - 29Operation: Annihilate! Apr. 13, 1967