The Enterprise tries to save an unidentified ship plunging into a supernova but is dragged into a universe where time runs backwards. Their only hope to return home is Commodore Robert April, the first commander of the Enterprise, who is onboard on a retirement trip.moreless
The Enterprise crew encounters an alien who visited Earth in ancient times and became known as the Mayan god Kukulkan.
After passing through an unusual energy field, the Enterprise computer develops a playful--and potentially lethal--personality.
Kirk leads a party to retrieve a religious relic that was stolen. However, he is faced with sabotage from within the group by someone who doesn't want the relic to be found, which will trigger an intergalactic jihad.moreless
While searching for a lost ship, Kirk, Spock, and McCoy are captured and placed in a zoo by advanced, telepathic aliens.
While exploring the planet Argo, Kirk and Spock are turned into water breathers.
The Enterprise and a Klingon ship must join forces to escape from a pocket universe that has been trapping starships for centuries.
The crew of the Enterprise finds themselves shrinking after being bathed with radiation.
The crew encounters Harry Mudd again, who is selling a fake love potion.
The Enterprise goes to the center of the galaxy, where they find a race of powerful aliens who once fled Earth.
In orbit around a dead star, the Enterprise comes across a huge starship inhabited by a parasitic life form that threatens the entire ship.