Notes
First published by Doubleday in 1968.

An expanded version of a novella first published in Galaxy magazine in 1967.

Publisher's Blurb
Banished from the complicated world of the far future to the barren emptiness of the remote past

1984 had come and gone, but still there were revolutionaries, dedicated to the overthrow of the Syndicalist Government. And like all totalitarian governments, that of 2006 needed a secure prison for its really dangerous opponents.

They found it, not in a remote area of the world, known or unknown, not in a distant galaxy a space-ship's voyage away, but beyond all limits known to man, a billion years in the past.

"Anyone who enjoys tales set in prehistory, as I do, should certainly look at this"
Brian Aldiss, Oxford Mail

"The author's story of men who move through the complicated worlds of the future and the empty worlds of the prehistoric past, further enhances his reputation as one of the elite among international science-fiction writers"
Eastern Times

Robert Silverberg is a winner of the coveted Hugo Award conferred by the World Science Fiction Convention. He is a past President of the Science Fiction Writers of America, and has written hundreds of science-fiction short stories and over twenty science-fiction novels.