When an accident causes Dr. McCoy to go temporarily insane, he escapes to a strange planet. There, the search party discovers a device left by a superior, vanished civilization, a time portal that plays the history of Earth for them - but then Bones jumps through it into the past, causing a change in history important enough to make the Enterprise vanish. Kirk and Spock, who fortunately made a tricorder recording, must attempt to go through to just before McCoy's arrival and stop him from changing history in the United States during the Great Depression, where they have no advanced technology available.
Did You Know?
No stardate is logged in the episode. Bjo Trimble assigned a stardate of 3134 based on Harlan Ellison
's original teleplay, which covered stardates 3134.6-8. See more
Kirk and Spock run down a 21st Street in Manhattan that curves; the real West 21st and East 21st Streets do not. See more
You know, I've convinced myself that this is all in a cordrazine hallucination. But I've decided you're not.
Script Supervisor is written as "SCPIPT SUPERVISOR...GEORGE A. RUTTER" in the credits. This happened on at least two other episodes in season one. See more
More recent prints omit the shot in which Rodent accidentally vaporizes himself with McCoy's phaser. Instead, the scene ends with him standing in the alley near the collapsed McCoy and looking bewildered. See more
Written by Ray Noble
, Jimmy Campbell
and Reginald Connelly
(as Reg Connelly)
Heard playing from the radio repair shop (with an uncredited vocal performer) and later as part of Fred Steiner's instrumental score (also uncredited)
Due to copyright issues, this music was replaced on some releases in the 1980s and 1990s See more