A drunk Irishman and a gay Asian walk into engineering...
Synopsis
The Enterprise has a dual mission: check in on a research station, and monitor the breakup of the planet. The research staff are all dead, frozen to death and apparently indifferent to their deaths. Starfleet's finest extra takes off his glove to scratch his nose and gets infected with—something.
The breakup of the planet requires precision control of their orbit. Meanwhile, the infection is spread by contact and makes the infected act drunk. McCoy can't figure it out. Sulu goes on the hunt for Cardinal Richelieu. And as said above, a drunk Irishman takes over engineering.
This is the second episode with Majel Barrett; she was the first officer in "The Cage," but now she's been demoted to nurse. She gets infected and starts hitting on Spock. Then Spock gets infected and has an emotional breakdown.
So the clock is ticking: Lieutenant Mick turned off the engines, and they need to cold start them. McCoy finds that the infection is an aberrant form of water, and starts treating the crew. Spock figures out how to get the engines going, but the overload sends them back in time. This will be used in increasingly preposterous ways, culminating in Kirk yelling at a San Franciscan, "Double dumbass on you!"
Commentary
This episode is a ton of fun, but there are two serious things that happen.
We get our first glimpse of the torrent of emotions hiding just below the vulcan surface: "My mother... I could never tell her I loved her. An Earth woman, living on a planet where love, emotion is in bad taste. I respected my father, our customs. I was ashamed of my Earth blood. Jim, when I feel friendship for you, I'm ashamed."
And we get our first look at Kirk's melancholy: "Love... you're better of without it, and I'm better off without mine. This vessel... I give, she takes. She won't permit me my life; I've got to live hers." Then later, "Never lose you. Never."
This point, in particular, we'll get back to in my least favorite of the original series movies, The Search for Spock.
