
Del lives in a world of many skies: by passing through the Hoops embedded in the ground, her people can walk freely between land that lies beneath a new set of constellations for every circuit they make around the edge of a Hoop. When archaeologists find a copy of the famed Book of All Skies, Del takes delivery of the manuscript in her role as conservator at the Museum of Apasa, hoping it will shed light on the fate of the Tolleans, the ancient civilisation that produced it. But when the book is stolen, the theft sets in motion a series of events that will see her travelling farther than she had ever imagined possible, and her understanding of her world and its history irrevocably transformed.
Author

Greg Egan specialises in hard science fiction stories with mathematical and quantum ontology themes, including the nature of consciousness. Other themes include genetics, simulated reality, posthumanism, mind transfer, sexuality, artificial intelligence, and the superiority of rational naturalism over religion. He is a Hugo Award winner (and has been shortlisted for the Hugos three other times), and has also won the John W Campbell Memorial Award for Best Novel. Some of his earlier short stories feature strong elements of supernatural horror, while due to his more popular science fiction he is known within the genre for his tendency to deal with complex and highly technical material (including inventive new physics and epistemology) in an unapologetically thorough manner. Egan is a famously reclusive author when it comes to public appearances, he doesn't attend science fiction conventions, doesn't sign books and there are no photos available of him on the web. Excerpted from Wikipedia.