Upon his return from a journey through the Guardian of Forever Kirk realizes that history has been altered and no one remembers Spock. An Andorian is now his First Officer and it appears that Spock met an untimely death during a childhood ritual on Vulcan. Spock must use the Guardian again and return to the Vulcan of his youth and restore his time line. Written by
Did You Know?
Writer D.C. Fontana
based the personality of Spock's pet sehlat on her pet cat named Bobby McGee. See more
Commander Thelin's collar is black but is blue in some shots during the meeting in the briefing room. See more
If that was supposed to be a joke, Spock, I have to remind you Vulcans don't tell jokes.
Times change, Doctor. Times change.