The End of Eternity is a science fiction novel by Isaac Asimov that explores the concept of time travel and its consequences. The story follows a time traveler named Andrew Harlan, who works for an organization called the Eternals that manipulates time to ensure a better future for humanity. However, Harlan starts to question the morality of the Eternals' actions and falls in love with a woman from the past, leading to a series of events that threaten the very existence of Eternity itself. The novel is a thought-provoking exploration of time, destiny, and the human condition.