The End of Eternity is a science fiction novel by Isaac Asimov. It tells the story of a secret organization called Eternity, which exists outside of time and works to ensure the stability of human history. The novel follows the protagonist, Andrew Harlan, as he becomes disillusioned with Eternity and begins to question the morality of their actions. He becomes involved with a woman from the past, which threatens to disrupt the timeline and the existence of Eternity itself. The novel explores themes of free will, the consequences of meddling with time, and the nature of power.