The Naked Time is one of the more entertaining Star Trek episodes, even though there is the usual percentage of danger involved. It's also one of those stories that uses its central plot device (in this case a virus) as a means to explore the essence of the show's characters, which is always welcome, given the series' general lack of long-term psychological development.
The aforementioned virus is brought on board after the exploration of a planet where everyone was killed without a logical explanation. Soon enough, though, it becomes apparent that the cause of death has reached the Enterprise: the disease removes the infected person's inhibitions, unveiling his or her most hidden desires. Because of this, Sulu starts running around shirtless with a sword in his hand, Spock discovers a female crew member is in love with him (it also turns out he isn't as cold and rational as he likes to make us believe, thanks to his human half) and Kirk is torn between his duties as captain and wishes of a more personal nature. Someone must come up with a solution fast, or this kind of behavior could mean the end of the Enterprise.
The Naked Time is essentially a 45-minute extravaganza where we get to see how Kirk and the others would behave if they lost their common sense and reverted to the animal side of their nature. The story is rather thin (it's basically a succession of entertaining skits), but the performances make it worth watching, especially Nimoy's work, which apparently was so well received by fans that the writers decided to play on Spock's dual nature as often as they could. A very wise decision indeed.
