END OF ETERNITY - Harper Collins

To the end of time... His name is Andrew Harlan. He was an Eternal: a member of a highly exclusive organization. He was a Technician, and his job was to range through past and present centuries, monitoring and even altering Time's myriad cause-and-effect relationships... But when he met Noys he fell victim to a phenomenon older than Time itself - love. It was then that he realized he must use the awesome technique of the Eternals to twist Time so that they might survive - together. The End of Eternity is science fiction for the connoisseur; it is mind-bending storytelling by the world's greatest modern master of SF - Isaac Asimov.