"All Our Yesterdays" (the penultimate story of the classic Star Trek series) brings us a great Spock/McCoy story weighed down by the sub-par Kirk story tacked to it.
Having learned nothing from the Minaran nova earlier this year, Enterprise stops by the star Beta Niobe at the last minute.
Planet Sarpeidon has 3 hours to live, but everyone has fled into the past except the old librarian Mr. Atoz, who runs the time machine.
Atoz provides discs of the past on DVD, very similar to the format I'm watching this series on. (No time travel has been forthcoming for yours truly- except the usual direction.)
Through the atavachron gateway, Kirk hears a women's scream and winds up in a medieval Europe-like time zone complete with musketeer costumes and hot-and-cold running open sewers. The constabulary seize Kirk on suspicion of witchcraft. Then later he gets free. A jowly lawyer was involved- I nodded off.
Spock and Bones land in an Ice Age when they go after the Captain. The boys in blue are starting to match their shirts when they are saved from freezing by the fetching Zarabeth, unjustly exiled by a tyrant. Zarabeth is villain and romantic lead all in one, and her hide bikini hides very little.
Atavachron travellers like her have their cell structure changed to match their new time period, and to return is to die. Atoz never prepared our heroes, so they only have a few hours to live. Just enough time to avoid burning at the stake, or a tryst with a cave woman. Assuming you feel like avoiding that sort of thing.
Spock tells Zarabeth he knows of no way to return her to her own time (Guardian of Forever and high warp solar slingshot notwithstanding). Then again, he thinks Vulcan is millions of light years away (it's thousands at most) so he's not having a great day for thinking.
He is becoming a Vulcan of the past: meat-eating and girl-kissing.
Sarpeidon goes the way of all things, with Atoz, Zarabeth, and Jowls de Whipt long dead in the past.
Mariette Hartley (who despite the ruling of the court of public opinion is not James Garner's wife) is so great as Zarabeth that she returned in several other Roddenberry SF projects and (as I vaguely recall) a couple of Star Trek novel sequels.
Tell me this shouldn't have been the last episode aired: we are tragically forced to leave love behind, and the final shot is the death of a star.