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?
When McCoy jumps through the portal, Capt Kirk is next seen finishing a dive to try to tackle him. However, he was 2-3 seconds late. He ended up 3 feet away from the portal with Spock between him and the portal. He probably would not have dived after nothing. See more
You were actually enjoying my predicament back there. At times, you seem quite human.
Captain, I hardly believe that insults are within your prerogative as my commanding officer.
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
Featured in Bring Back... Star Trek
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