In orbit around a dead star, the Enterprise comes across a huge starship inhabited by a parasitic life form that threatens the entire ship.

Spock must return to his own past on Vulcan to prevent his death as a youngster.

The crew of the Enterprise races to find a way to stop a cloud from destroying inhabited planets.

The men of the Enterprise are victimized by a race of beautiful women who stay immortal by draining the lifeforce of men.

The Enterprise finds missing trader and philanthropist Carter Winston, but he may not be what he appears to be.