Time and Again (sometimes written as Time & Again) is a 1951 science fiction novel by American writer Clifford D. Simak. An alternate paperback title was First He Died; it was also serialized (with a different ending) as Time Quarry. The story is about a long-lost spaceman returning to Earth after 20 years from a planet in a distant star system, where he was affected by aliens with psychic abilities. He returns to find Earth has changed. Source: Wikipedia (en)