The End of Eternity

In this standout work of science fiction, Andrew Harlan is tasked with creating small but significant changes to the course of history in order to benefit humanity. But when he falls in love with a woman from the real world, he risks everything to bring her into his own world of Eternity. As punishment, he must carry out a devastating task: killing the woman he loves before she inadvertently destroys their entire society. This work from Isaac Asimov is widely considered a masterpiece of the genre and a must-read for fans of science fiction.