By turns thrillingly expansive, joyously inventive and utterly engrossing *****.
SFX magazine
An absorbing collaborative effort from two SF giants...a marriage made in fan heaven - Pratchett's warmth and humanity allied to Baxter's extraordinarily fertile science-fictional imagination...there's much to enjoy...a charming, absorbing and somehow spacious piece of imagineering
- Adam Roberts, GUARDIAN
The idea of parallel Earths is one of the most enduring that science fiction has given us, but rarely has it been explored with quite so much gusto as in this new novel by two of the giants of British speculative fiction...a triumph...accessible, fun and thoughtful
- David Barnett, INDEPENDENT
***** Literary alchemy...In the hands of Pratchett and Baxter, the possibilites are almost infinite...a story that revels in big ideas...you can sense the excitement of the authors as they toy with the labyrinthine possibilities of their premise, and it's infectious...thrillingly expansive, joyously inventive and utterly engrossing
SFX
[Pratchett] succeeds in working seamlessly with Baxter...adding a welcome shot of fun to the world of science fiction
- Alison Flood, SUNDAY TIMES