Robert Silverberg - The Time Hoppers

ROBERT SILVERBERG confronts the paradoxes of time travel in a brilliant novel of the 25th century, when the only escape from suffocation in a totally controlled environment is to hop backward through time.
Since time hopping rearranges the past on which the structure of current existence is based, it must be stopped - but not too quickly. For the history of the 1970's includes the arrival of hoppers who have not yet left the 2490's - and whose departure thus must not be stopped!

Robert Silverberg has been a professional writer since 1955, widely known for his science fiction and fantasy stories. He is a many-time winner of the Hugo and Nebula awards, was named to the Science Fiction Hall of Fame in 1999, and in 2004 was designated as a Grand Master by the Science Fiction Writers of America.