Ancient alien minds are given control of Captain Kirk’s and First Officer Spock’s bodies.

The crew of the Enterprise discovers Klingon interference in the development of a formerly peaceful planet and is forced to help maintain a balance of power.

The crew of the Enterprise encounters an energy-draining field which may be able to destroy the galaxy.

The Enterprise visits a planet with an Earth-like 1920s gangster culture.

Captain Kirk and his companions are abducted into slavery and trained to fight as gladiators for the gambling entertainment of three disembodied beings.

The Enterprise must protect a very important shipment of grain from both Klingons and some adorable creatures called tribbles.

A series of bizarre murders points to Mr. Scott as the prime suspect.

Captain James T. Kirk becomes obsessed with destroying a deadly entity he once encountered in his youth.

Strange radiation exposes the command crew of the Enterprise to the effects of rapid aging.

The crew of the Enterprise become entangled in a planet’s tribal power struggle.