"This fantastic novel is a mix of Niven hard science and a time-travel concept to boggle the mind...even after the last line the feeling remains of the story still rushing on into the magic distance of the universe."
- A.E. van Vogt
"Niven's intoxicating concepts, ideas, scientific extrapolations, and exotic hardware buffle up from every page. Rich in imagination and astonishing in breath ... will challenge the most sophisticated readers."
- ALA Booklist
- Kirkus Reviews
"His tales have grit, authenticity, colorful characters and pulse-pounding narrative drive. Niven is a true master!"
- Frederik Pohl
"Larry Niven is one of the giants of modern science fiction."
- Mike Resnick
"Our premier hard SF writer."
- The Baltimore Sun
"Niven...lifts the reader far from the conventional world -- and does it with dash."
- The Los Angeles Times
"Niven...juggles huge concepts of time and space that no one else can lift."
- Charles Sheffield
"In creating a geologic world and in the interactions between humans and aliens, Niven is superb."
- Boston Sunday Globe
"One of the genre's most prolific and accessible talents."
- Library Journal
"The scope of Larry Niven's work is so vast that only a writer of supreme talent could disguise the fact as well as he can."
- Tom Clancy