By Any Other Name

A small group of superior alien beings take the form of humans in order for them to hijack the Enterprise. They need the ship so they can return to their old world that is beyond the Great Barrier. They turn almost the whole crew into these clay balls, except for Kirk, Spock, Scotty, and Bones, whom they need to help them run the ship. The only weakness the hijackers seem to have is that since they're in human form for the time being, they're vulnerable to human emotions. The episode starts out very serious and dreary, but ends up to the amusing as the crew exploits the human emotions of these so called, "superior beings". The best one is Kirk and Spock driving their leader insane with jealously over a woman. Excellent episode.