Star Trek: TOS 1.20: "The Alternative Factor"

Kirk, pal, you could've thrown the crazy one in space-jail. Trapping both in the parallel universe corridor "for all eternity" wasn't even close to the only alternative. Then again, it allowed for your fine "What of Lazarus?" moment on the bridge.

Strangely, I had no memory of this episode.

yr: 2267
sd: 3087.6
ad: 30 Mar 1967