| The protagonist(s) in this story are symbiotic creatures who can only see in all directions when they work together because the laws of physics in their world have strange implications for the way that light can travel.
This novel is clearly a philosophical descendant of Flatland and very similar to Egan's recent Orthogonal Series which takes place in a universe whose spacetime metric is entirely positive (unlike ours in which one of the four components is negative).
The relevant mathematics here is that of hyperbolic geometry. In fact, the cover of the book shows a planet whose surface is a hyperboloid! Hence, this novel ought to be compared with Christopher Priest's Inverted World and Stephen Baxter's Pacific Mystery. Of course, being Greg Egan, he takes it much farther than either of those two authors. Egan is known for writing "hard science fiction" in which plot and character development take a back seat to an exploration of the consequences of some unusual technology or physical laws. In their review, Publisher's Weekly wrote: "Impressively bizarre . . . Egan may have out-Eganed himself with this one."
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