First trade edition of one of Simak's most wild rides, "featuring an educated Neanderthal, a biomechanical sabertooth tiger, aliens that move about on wheels, a man who time-travels using an unreliable device implanted in his brain, meeting a ghost, trolls, banshees, goblins, a dragon and even Shakespeare himself" (Wikipedia). Originally serialized in Galaxy Science Fiction magazine, and then a nominee for the Hugo Award in 1969.
Very minor rubbing to jacket spine's foot and crown, some rubbing along fore edge. Some small foxing on page edges. Book stamp on pastedown behind jacket sleeve.