Kirk, Spock, McCoy and a couple of red shirts beam down to the surface of a planet in answer to a fake distress call. There they are overpowered by a small group of human-looking aliens from the Andromeda galaxy, led by Rojan. Their galaxy will be uninhabitable within a few thousand years, so they intend to conquer ours, to give themselves a new home. The aliens' spacecraft had been damaged by the energy barrier around the galaxy, and they need the Enterprise to return home, enhancing its engines so that the journey will "only" take 300 years. They take over the Enterprise using their two main weapons - a paralyzing beam, and a ray that can reduce a person to a gray block of material - revival only being possible if the block is not damaged. After successfully negotiating the energy barrier, the aliens reduce all the crew into the gray blocks, with the exception of Kirk, Spock, McCoy and Scott, who must somehow overcome the aliens, revive the crew and return home. Written by
Did You Know?
A three-dimensional chess set is often seen in the series, but a three-dimensional checkers set can be seen in the rec room in this episode. It is later destroyed in a fight. See more
The part in Rojan's hair changes from left to right and back. It is changed only in the face-on shot a minute or so before the end. See more
We do not colonize. We conquer. We rule! There's no other way for us.
In other words, "The galaxy isn't big enough for both of us!"