Captain Kirk (William Shatner) and Mr. Spock (Leonard Nimoy) travel back to Earth during the Great Depression to correct a temporal anomaly.
While there, Kirk falls in love with the altruist Edith Keeler played somewhat surprisingly by Joan Collins. But a makeshift computer, rigged by Spock from his Tricorder and some vacuum tubes, informs them that Keeler must die or Nazi Germany will prevail in World War II.
In the provocative “City on the Edge of Forever,” Kirk balances his one true love against the lives of untold millions. No adventure ever affected the captain — or us — so deeply.
Original Airdate: April 6, 1967