The City on the Edge of Forever

"The City on the Edge of Forever" is a classic "Star Trek" episode where the crew of the USS Enterprise discovers a time portal that takes them to 1930s Earth. Dr. McCoy accidentally alters history by saving a woman named Edith Keeler, who was destined to prevent the U.S. from entering World War II early. Her survival would cause a different, darker future. To restore the timeline, Captain Kirk and Spock must make a difficult choice: allow her to die or change history forever. The episode explores themes of sacrifice, the impact of individual actions on the future, and moral dilemmas.