One of the problems with brilliant writers is that some of their short stories can find themselves duplicated in different collections of theirs. This book in an excellent example of such an occurence. The contents of both collections 'Crystal Nights' and 'Dark Integers' can be found in the larger 'Oceanic' collection, available from amazon.co.uk, except for two stories: 'Luminous' already present in Egan's previous anthology of the same title, and 'TAP' available online at the author's site. Of course, one might argue that two smaller volumes are easier to handle than a larger one, although acquiring the two may end up costing you twice as much. There can be no argument however about the sheer scientific brilliance and the profound philosophy in which Greg Egan continually excells. I thought of giving this book four stars because of this publishing duplication, but after all, there is only one Greg Egan. (Grand Master Egan, again I bow down at your lotus feet!)