Show Stardate Episode Title
4040.7 Bread and Circuses
The Enterprise finds the wreckage of the S.S. Beagle, with no survivors, orbiting near the Planet 892-IV. (released March 15, 1968)
4187.3 The Slaver Weapon
When a rare artifact of the Slaver culture, a time-stopping stasis box, is being delivered to Starbase 25, it registers that another one is nearby. (released December 15, 1973)
4202.9 The Doomsday Machine
Sent to investigate the destruction of several planetary systems, the Enterprise discovers a crippled starship, the U.S.S. Constellation, floating in space. (released October 20, 1967)
4211.4 A Private Little War
The Enterprise is sent to the planet Neural to gather vegetation samples, were years ago, Kirk had headed a planetary survey and became friends with one of the planet's leader, Tyree. (released February 2, 1968)
4307.1 The Immunity Syndrome
Bound for shore leave after a particularly difficult mission, the Enterprise receives an emergency rescue call. Contact has been lost with system Gamma 7A and Starbase 6 wants Kirk to check it out. (released January 19, 1968)
4372.5 Elaan of Troyius
Two United Federation of Planets members, Elas and Troyius, suffered war for centuries. With Klingon Empire expansion approaching the planets' system the Federation sends the Enterprise to lend assistance in a peace negotiation. (released December 20, 1968)
4385.3 Spectre of the Gun
Kirk ignores an alien buoy that warns the Enterprise that it is trespassing into Melkotian space and continues forward when the Melkots transport Kirk, Spock, McCoy, Scotty, and Chekov to a recreation of Earth's wild west. (released October 25, 1968)
4513.3 I, Mudd
An android pretending to be a member of the Enterprise crew, takes control of the starship and her crew, taking them to an unnamed planet where Kirk discovers an old nemesis... Harry Mudd. (We first meet Mudd on stardate 1329.1.) (released November 3, 1967)
4523.3 The Trouble With Tribbles
When the Enterprise receives a top priority order to protect a shipment of quadrotriticale grain on Space Station K-7, Kirk is irritated to be guarding a shipment of wheat. This episode happens at the same time as the Deep Space 9 episode Trials and Tribble-ations. (released December 29, 1967)
4598.0 A Piece of the Action
The planet Iotia's last visit by the Federation was by the U.S.S. Horizon... a hundred years before. Realizing the lapse in monitoring the planet, the Federation sends the Enterprise to observe the progress of Iotia's population. (released January 12, 1968)
4657.5 By Any Other Name
When the Enterprise answers a distress call from a small planet, the landing party is captured by a group of agents from the Kelvan empire, located in the distant Andromeda galaxy. (released February 23, 1968)
none given The Omega Glory
The Enterprise finds a crewless starship, the U.S.S. Exeter, in orbit around the planet Omega IV. The boarding party from the Enterprise contracts a virus that may have killed the Exeter's crew, but the biosphere on Omega IV is found to contain an immunity. (released March 1, 1968)
4729.4 The Ultimate Computer
The Enterprise is chosen to be the test ship for the new M-5 Multitronic computer system, a computer meant to be able to run a starship without human intervention. (released March 8, 1968)
4768.3 Return to Tomorrow
A landing party beams down to the long-dead planet, Arret. They find a deep cave containing three living, disembodied, highly intelligent beings. (released February 9, 1968)
4842.6 The Paradise Syndrome
Investigating a planet in danger of collision with an asteroid, Captain Kirk, Mr. Spock, and Doctor McCoy discover both Native American inhabitants and a strange alien obelisk. While examining the obelisk, Kirk is accidentally trapped inside. (released March 8, 1968)
none given Assignment Earth
Sent back in time to find out how Earth managed to survive without destroying itself, the Enterprise inadvertently beams aboard a space traveler, Gary Seven, along with his black cat, Isis. (released March 29, 1968)
4978.5 Mudd's Passion
The Enterprise is ordered to find Harry Mudd, a Federation outlaw, who is accused of selling a fake love potion to miners. (released November 10, 1973)