Episode Title: "THE CITY ON THE EDGE OF FOREVER"
Production Number: 28
Original Air Date: 04-06-67
The U.S.S. Enterprise is in orbit of a planet where ripples in time are causing turbulent waves of space displacement. One jolt to the ship injurs Lt. Sulu when the helm console explodes on the Bridge. Dr. McCoy uses cordrazine -- a potent drug -- to revive him. Another jolt causes McCoy to accidently inject himself with a high dose of the drug, putting him in a paranoid manic state. He beams down to the planet, near the center of the time disturbance.
Captain Kirk leads a landing party to the planet to search for McCoy among the planet's ancient ruins, which are 10,000 centuries old. They discover a glowing stone arch in the ruins that is the source of the time displacement. The arch calls itself the Guardian of Forever, which has existed since before Earth's sun burned hot in space; it can create a time portal to display other points in history. While Spock is scanning Earth's past through the time portal, the delusional McCoy jumps through the portal, and the landing party loses contact with the Enterprise. McCoy has changed the past and the Enterprise no longer exists.
Spock scans history again and he and Kirk jump through the portal to find McCoy. They arrive in New York City in 1930, days before McCoy arrives, where they meet Edith Keeler, a visionary social worker. Spock uses contemporary equipment to view the records on his tricorder, and determines that after McCoy's interference in the timeline, Keeler will found a peace movement that will delay America's entry into World War II, allowing Germany to win the war. In the original timeline, Edith Keeler would be killed in a traffic accident in 1930, so Kirk and Spock must prevent McCoy from saving her, in order to restore history to the way it was.
Factoid: About 100 years after 1930, a famous novelist will write a classic using the theme "Let me help" -- recommending those three words even over "I love you." He will come from a planet circling the far left star in Orion's Belt.
McCoy: "I'm a surgeon, not a psychiatrist. I am Leonard McCoy, senior medical officer aboard the U.S.S. Enterprise."
Guest Characters: Transporter Chief Lt. Kyle, Lt. Galloway, Lt. DeSalle, *Guardian of Forever
KEY: [brackets]=illusions *star=first appearance