Star Trek: 2x4
Mirror, Mirror
A transporter mishap swaps Captain Kirk and his companions with their evil counterparts in a parallel universe. In the so-called Mirror Universe, the Enterprise is a ship of the Terran Empire, an organization as evil as the United Federation of Planets is benevolent.
2 - 1Amok Time Sep. 15, 1967
2 - 2Who Mourns for Adonais? Sep. 22, 1967
2 - 3The Changeling Sep. 29, 1967
2 - 4Mirror, Mirror Oct. 06, 1967
2 - 5The Apple Oct. 13, 1967
2 - 6The Doomsday Machine Oct. 20, 1967
2 - 7Catspaw Oct. 27, 1967
2 - 8I, Mudd Nov. 03, 1967
2 - 9Metamorphosis Nov. 10, 1967
2 - 10Journey to Babel Nov. 17, 1967
2 - 11Friday's Child Dec. 01, 1967
2 - 12The Deadly Years Dec. 08, 1967
2 - 13Obsession Dec. 15, 1967
2 - 14Wolf in the Fold Dec. 22, 1967
2 - 15The Trouble With Tribbles Dec. 29, 1967
2 - 16The Gamesters of Triskelion Jan. 05, 1968
2 - 17A Piece of the Action Jan. 12, 1968
2 - 18The Immunity Syndrome Jan. 19, 1968
2 - 19A Private Little War Feb. 02, 1968
2 - 20Return to Tomorrow Feb. 09, 1968
2 - 21Patterns of Force Feb. 16, 1968
2 - 22By Any Other Name Feb. 23, 1968
2 - 23The Omega Glory Mar. 01, 1968
2 - 24The Ultimate Computer Mar. 08, 1968
2 - 25Bread and Circuses Mar. 15, 1968
2 - 26Assignment: Earth Mar. 29, 1968