First off, to borrow an old cliché, don't judge this book by its cover. The cover, of a suited warrior firing a laser rifle against a backdrop of explosions, gives the impression that this is a military sci-fi novel (a genre which I'm not terribly interested in). Instead, this book, the second in a series, has much more in common with Larry Niven's _Ringworld_, as it deals with the interplay between races on a giant helical constructed world, wrapped around a star like a slinky, with thousands of cylindrical worlds strung along like beads on a necklace.

However much the construct may invite comparisons to Niven's Ringworld, though, Brown's worldbuilding isn't quite so engrossing. The structure of the Helix allows for lots of variety in environments and races, but leaves a lot of the technical underpinnings (for instance, how do the individual worlds have gravity?) to be either entirely unexplained or brushed off as "technology so advanced we can't understand it". The concept sounds very hard-SF, but the execution leaves something to be desired.

That said, the book isn't at all bad, though it's not likely to end up as my pick for this year's P.K. Dick award (for which it is one of seven nominees). I just hoped for a little more Niven-like exploration of the hard-SF concept that instead acts as little more than an interesting background for the story itself.