Space. The Final Frontier. The U.S.S. Enterprise embarks on a five year mission to explore the galaxy. The Enterprise is under the command of Captain James T. Kirk with First Officer Mr. Spock, from the planet Vulcan. With a determined crew, the Enterprise encounters Klingons, Romulans, time paradoxes, tribbles and genetic supermen led by Khan Noonian Singh. Their mission is to explore strange new worlds, to seek new life and new civilizations, and to boldly go where no man has gone before.
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.
The starship Enterprise and its heavily-damaged sister ship, the USS Constellation, must work together to stop an alien planet-killing machine headed for the heart of Federation territory.
Captain Kirk and his companions are abducted into slavery and trained to fight as gladiators for the gambling entertainment of three disembodied beings.
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.