1. Amok Time
Aired: Sep 15, 1967In the throes of his Pon Farr mating period, Spock must return to Vulcan to m...
2. Who Mourns for Adonais?
Aired: Sep 22, 1967A powerful being claiming to be the Greek god Apollo appears and demands that...
3. The Changeling
Aired: Sep 29, 1967A powerful artificially intelligent Earth probe, with a murderously twisted i...
4. Mirror, Mirror
Aired: Oct 6, 1967A transporter accident places Captain Kirk's landing party in an alternate un...
5. The Apple
Aired: Oct 13, 1967Primitive inhabitants of Gamma Trianguli VI worship a god who orders them to ...
6. The Doomsday Machine
Aired: Oct 20, 1967The USS Enterprise encounters the wrecked USS Constellation and its distraugh...
7. Catspaw
Aired: Oct 27, 1967Very alien visitors to our galaxy attempt to connect with human consciousness...
8. I, Mudd
Aired: Nov 3, 1967Harry Mudd returns with a plot to take over the Enterprise by stranding the c...
9. Metamorphosis
Aired: Nov 10, 1967While returning to the Enterprise aboard the shuttlecraft, Kirk, Spock, McCoy...
10. Journey to Babel
Aired: Nov 17, 1967The Enterprise hosts a number of quarrelling diplomats, including Spock's fat...
11. Friday's Child
Aired: Dec 1, 1967The Federation clashes with the Klingon Empire over mining rights to Capella ...
12. The Deadly Years
Aired: Dec 8, 1967A landing party from the Enterprise is exposed to strange form of radiation w...
13. Obsession
Aired: Dec 15, 1967Capt. Kirk obsessively hunts for a mysterious cloud creature he encountered i...
14. Wolf in the Fold
Aired: Dec 22, 1967Kirk and the Enterprise computer become detectives after Scotty is accused of...
15. The Trouble with Tribbles
Aired: Dec 29, 1967To protect a space station with a vital grain shipment, Kirk must deal with F...
16. The Gamesters of Triskelion
Aired: Jan 5, 1968Kirk, Uhura and Chekov are trapped on a planet where abducted aliens are ensl...
17. A Piece of the Action
Aired: Jan 12, 1968The crew of the Enterprise struggles to cope with a planet of imitative peopl...
18. The Immunity Syndrome
Aired: Jan 19, 1968The Enterprise encounters a gigantic energy draining space organism that thre...
19. A Private Little War
Aired: Feb 2, 1968Peaceful, primitive peoples get caught up in the struggle between superpowers...
20. Return to Tomorrow
Aired: Feb 9, 1968The Enterprise is guided to a distant, long-dead world where survivors of an ...
21. Patterns of Force
Aired: Feb 16, 1968Looking for a missing Federation cultural observer, Kirk and Spock find thems...
22. By Any Other Name
Aired: Feb 23, 1968Galactic alien scouts capture the Enterprise for a return voyage and a prelud...
23. The Omega Glory
Aired: Mar 1, 1968Responding to a distress signal, Kirk finds Captain Tracey of the U.S.S. Exet...
24. The Ultimate Computer
Aired: Mar 8, 1968Kirk and a sub-skeleton crew are ordered to test out an advanced artificially...
25. Bread and Circuses
Aired: Mar 15, 1968The Enterprise crew investigates the disappearance of a ship's crew on a plan...
26. Assignment: Earth
Aired: Mar 29, 1968While back in time observing Earth in 1968, the Enterprise crew encounters th...