#46: All Our Yesterdays
In case you forgot: The Enterprise's mission is to warn the people of Sarpeidon that their doom is imminent, as their sun is about to supernova. The Power Trio beams down only to find the planet bereft of people except one librarian and assorted robotic versions of himself. Turns out that everyone on Sarpeidon already knows about their dying, exploding sun; it seems they sunk their science into time travel rather than interstellar space exploration and have escaped their doom by hiding in the planet's past. Of course the Power Trio get sucked into the past, too—Kirk into some kind of Puritan witchhunt, Bones and Spock into an ice age—but they resolve it just in time. Also, Spock falls in love.
The "time travel as a means to escape the present" idea is probably in my list of top ten coolest throwaway ideas ever used on Star Trek. That's the stuff entire series of novels are written about. But Trek uses it as the Monster of the Week. This was one of two contributions of Jean Lisette Aoreste, not a writer by trade but rather a librarian. (The other episode she wrote was Is There in Truth No Beauty? which we'll come to later in this countdown.) Judging by her skimpy Wikipedia entry, she seemed to have stuck with librarying as there scant little about her online. The last I can find on her is that she was co-editor on Directory of scholarly and research publishing opportunities: a guide to academic publishing opportunities in the humanities, social sciences, and science and technology. in 1971.
Despite such a strong and interesting premise, the story quickly flounders. There is idiot ball all over All Our Yesterdays. The entire adventure happens because the librarian (hah, weird to think about there being a librarian character in this script, considering who wrote it) doesn't realize that the Power Trio has their own escape route and is incredibly pushy about getting them out. Then Spock somehow "regressing" to a previous state of Vulcan evolution? What? Just so that he can have the alien girl of the week? Weak.
Kirk's adventure is more bearable, but not by much. Not enough to save this episode.