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 US during the Great Depression, where they have no advanced technology available. Written by
Did You Know?
Keeler tells McCoy his blue uniform hardly looks like it's from the U.S. Navy. DeForest Kelley
filmed naval training videos in real life. See more
As Kirk and Edith Keeler stroll through town, a radio plays "Goodnight, Sweetheart", a song from 1931, one year after the setting of this episode. See more
If you can leave right away, I can get you 5 hours of work at 22 cents an hour.
[seeing Spock's arcing and sparking tricorder adapter
What... what on earth is that?
I am endeavoring, ma'am, to construct a mnemonic memory circuit using stone knives and bearskins.
Referenced in Frasier: Star Mitzvah