Charlie Evans, the sole survivor of a transport crash, is transferred to the Enterprise from a different ship. Why are they so eager to rid themselves of him, though? There's more to Charlie than meets the eye...

The Enterprise picks up a intergalactic conman, Harry Mudd, and three incredibly beautiful women who harbor a dark secret.

Nurse Christine Chapel is reunited with her old fiance on Exo III, but the scientist has plans for Captain Kirk and the Federation.

The Enterprise encounters a vast alien ship that threatens the Enterprise with destruction.

Kirk pits the Enterprise against an invisible spaceship testing the Federation's defenses.

The crew of the Enterprise are held captive by an alien who turns out to be the Greek god Apollo.

The crew of the USS Enterprise deals with an indestructible planet-destroying space probe.

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.