Star Trek: TOS - "The Tholian Web"
The Enterprise goes nosing around one too many times, pisses off some gang bangers called the Tholians, and Kirk nearly gets his ass handed to him in another universe.
Also known as just another Wednesday afternoon in Starfleet!
Our heroes come across sistah ship the Intrepid, all pale green and glowing, looking like it was redecorated by Obi-Wan Kenobi after he moved in with the Force. This area of space is unstable (much like Amy Winehouse around a pub) and causes a kind of insanity in people (much like Mel Gibson around Jews). It's also "winking out" the Intrepid into another universe. Bummer!
Kirk, being all brave and stuff, gets caught on the other side and Spock, McCoy and the crew try to save him while keeping the area's true resident's, the Tholians, outta their space-hair. This puts Spock and McCoy at each other's throats (like Amy Winehouse around Mel Gibson).
They sacrifice a goat in engineering or something, and everyone is happy in the end. (Some of that may not be entirely true, except the happy ending part).
A better third season effort, once again boiling down to conflict between members of The Big Three, in this case Spock and McCoy. There's a great scene where they have to go to Kirk's quarters to listen to his last orders to them, which includes some much needed advice as well. And even though Kirk is physically not in this episode so much, his presence is felt, most especially by Spock and McCoy.
The Tholians are an interesting race, with their diamond-shaped ships and funky energy web. I haven't seen the Remastered version, but I wonder if we see the Enterprise from a distance totally encased in the web like a fly in amber (unlike the original version where they just animated some lines over stock shots of the Enterprise - you never got a sense the web was three dimensional). The Tholians appearance was also pretty ingenious, as you can see directly below. This beats TNG's usual alien-from-the-valley.
Nichelle Nichols and Walter Koenig got a little more to do in this story, with Uhura seeing the captain and Chekov going nutso. I think the only regular really slighted was George Takei, but at least he had a little "action beat" with his altercation with Chekov, so he wasn't just sitting in his chair staring at the viewer the whole episode.