13 Darkest Star Trek: The Original Series Moments
5. Garth's Insanity In Whom Gods Destroy
Kirk and Spock are held prisoner by Garth of Izar, a Starfleet hero who has fallen victim to insanity. He has taken over the asylum where he had been receiving treatment and now plans to take control of the Enterprise. Once the Enterprise is his to command, he intends to strike out and take revenge on his former crew.
Not only do his quickly-changing moods make him a dangerous opponent, but he also possesses shape-shifting abilities, taught to him by the natives of Antos IV. With these abilities, he can alter his appearance to appear as literally anyone. This talent combined with his capricious moods makes it imperative he does not get anywhere near a starship.