Memory Alpha's In Universe Timeline
Tomorrow Is Yesterday - The City on the Edge of Forever - Space Seed.

The Naked Time - The City on the Edge of Forever - I, Mudd.


While the Federation starship USS Enterprise is investigating temporal disturbances from a nearby planet, Lt. Sulu is injured in an explosion. Chief Medical Officer Dr. McCoy gives him a shot of cordrazine and accidentally injects himself with an overdose when the ship is shaken. Delusional, he flees from the Bridge and to the Transporter Room, beaming himself down to the planet.

Captain Kirk beams down with a landing party to look for McCoy and finds the source of the time distortions, an ancient glowing ring with an aperture the height of a human. The "Guardian of Forever" explains that he is a doorway to any time and place. While Spock is recording historic portal images, McCoy escapes through it, into the past. Suddenly the landing party loses contact with Enterprise and is informed that the past has been altered and the ship - along with the entire Federation - no longer exists.

Since the timeline must be repaired, the Guardian lets Kirk and Spock go after McCoy at the same image in time that McCoy went in. Before the pair depart, Kirk tells the landing party to enter the portal and make new lives for themselves in the past if he and Spock fail to return. Kirk and Spock arrive in New York City during the 1930s Great Depression. After stealing some clothes to blend in, they meet a woman named Edith Keeler, who runs the 21st Street Mission. They offer to work for her. Spock begins to construct a processor to interface with his tricorder to find out how McCoy altered history.

Kirk begins to fall in love with Edith, whom he finds remarkable. She is interested in man's future and the stars. McCoy stumbles into the mission where Edith takes him in, unbeknownst to Kirk. Spock finishes his work and, reviewing the Guardian's images of the original and altered timelines, discovers that Edith was supposed to have died in a traffic accident, which was somehow prevented by McCoy. Instead, Edith lived on to start a pacifist movement which influenced the United States sufficiently to delay its entrance into World War II, thus allowing Nazi Germany time to develop an atomic bomb and win the war. Kirk knows that Edith must die in order for time to return to normal. Meanwhile, Edith nurses McCoy back to health, and he tells her his story. Though Edith is skeptical, she tells McCoy that he would like her eccentric new boyfriend.

Later, as Kirk and Edith are walking to the movies, Edith mentions Dr. McCoy. Alarmed, Kirk tells Edith to stay there before running to find Spock. The three friends meet in front of the mission. As a curious Edith crosses the street to join them, she steps in front of a fast-moving truck. Instinctively, Kirk reacts, but freezes when Spock stops him. McCoy is restrained by Kirk as Edith is knocked down and killed. McCoy tells Kirk that he could have saved her. “Do you know what you just did?" he says. Spock responds quietly, "He knows, Doctor. He knows."

With Edith's death, history reverts to its original form. Kirk, Spock and McCoy return to the Guardian's planet where, as far as the rest of the landing party are concerned, the three have only been away for a few minutes. The Guardian then says, "Time has resumed its shape. All is as it was before. Many such journeys are possible. Let me be your gateway." Enterprise contacts the landing party and the traumatized Kirk responds with the instructions, "Let's get the hell out of here."

Errors and ExplanationsEdit

The Nitpicker's Guide for Classic TrekkersEdit

Plot OversightsEdit

  1. McCoy managing to escape from the Bridge before Spock could use the nerve pinch. The overdose appears to have temporarily given McCoy enough speed and strength to escape before Spock can grab him - an effect that partly wears off by the time the security guards overpower him on the planet.

Equipment OdditiesEdit

  1. Spock's tricorder only being able to playback recordings when attached to a computer. The independent playback feature could have been disabled somehow.

Internet Movie DatabaseEdit

Plot holesEdit

  1. The Guardian of Forever first speaks in response to Kirk's questioning of its origin, by responding "A question." Moments earlier, Kirk had asked the same question in slightly different wording, with no response, though this question was directed to Mr. Spock. The Guardian may not have heard the question the first time.
  2. McCoy changes the past by stopping Edith from getting hit by a car like she would have if he had not gone back. However, it was the presence of McCoy and Kirk that led to her being in the road to get hit by the car, if they hadn't gone back she would not have been hit by the car anyway. She must have been crossing the road when the car came through in the original timeline.

Nit CentralEdit

  1. John A. Lang on Wednesday, June 09, 2004 - 7:37 pm: How come nobody used their phaser on heavy stun on McCoy when they found him on the planet? The effects of the phaser beam could have caused a serious reaction to the excess cordrazine in McCoy's body.
  2. Kinggodzillak on Tuesday, May 31, 2005 - 2:15 pm: What exactly is supposed to be wrong with Sulu at the start of the ep? I know the console exploded, but he clearly isn't burned at all. Did he just bang his head as he hit the floor, or something? Todd Pence on Tuesday, May 31, 2005 - 6:11 pm: Sulu could have received a massive electrical shock, which would not necessarily leave any visible burn marks on his body.


  1. The stardate listed here was assigned by Bjo Trimble, based on Harlan Ellison's original teleplay, which covered stardates 3134.6-8.

The Original Series Season 1
Pilot episodes: The Cage I Where No Man Has Gone Before
Regular episodes: The Corbomite Maneuver I Mudd's Women I The Enemy Within I The Man Trap I The Naked Time I Charlie X I Balance of Terror I What Are Little Girls Made Of? I Dagger of the Mind I Miri I The Conscience of the King I The Galileo Seven I Court Martial I The Menagerie Part 1 I The Menagerie Part 2 I Shore Leave I The Squire of Gothos I Arena I The Alternative Factor I Tomorrow Is Yesterday I The Return of the Archons I A Taste of Armageddon I Space Seed I This Side of Paradise I The Devil in the Dark I Errand of Mercy I The City on the Edge of Forever I Operation: Annihilate!