Egan's first novel for 6 years is set in a very far future where an evolved humanity has spread out to inhabit the galaxy's spiral arms, where lifespans are measured in millennia and travel is possible almost anywhere in the galaxy. The exception is the central galactic bulge which is inhabited by the aptly named Aloof, who exist in splendid isolation and firmly but gently repel all attempts to go there.
Sounds pretty intriguing, doesn't it? The Aloof are a mystery. Obviously highly advanced, but unwilling to interact with humanity. Until two intrepid humans accept an invitation to travel to into Aloof territory to examine a strange rock world inhabited by sentient insect-like creatures.
Still sounds intriguing, doesn't it? As always, Egan is concerned with hard science - mathematics, physics, genetics and astronomy - and indeed the nature of scientific discovery. And therein lies the problem. Incandescence suffers from the same shortcoming as did Schild's Ladder - too much science, not enough fiction. Both the human and insectoid characters are painted far too thinly to arouse any real emotion and the dialogue serves mainly as a vehicle for explaining the science rather than giving any insight into the characters themselves. As a reader I felt a kind of intellectual detachment from the events - like I was watching but not particularly engaged. Rather like the Aloof, in fact.
Nonetheless, the science is intriguing, even for a non-scientific type like me, and the ideas are really big. So, if that's your thing, you'll probably enjoy it more than I did. For me, though, the biggest most intriguing mystery of all, the Aloof themselves, remained unsolved. Indeed, I gleaned little insight into their nature or their motives. For me they remained as aloof as ever.
I still think Egan is one of the best SF writers around, but Incandescence is not his most engaging work.