This is Greg Egan's first book since 2002, and his first short story collection for a decade. It was worth waiting for. There are five longish stories in this collection, including the previously published Luminous and its sequel Dark Integers, two stories set in the far future world of the Amalgam (the setting for Egan's upcoming novel Incandescence) and the award-winning Oceanic. Although there are a good many Egan stories that have yet to be collected, it was worth reprising Luminous in this collection because the title story has more impact when you have Luminous fresh in your mind. Together they make an exciting double. Not many writers could take two stories about the most abstract of mathematical concepts and turn them into such thrilling reading, but Egan has done it really successfully here. The standout story in the collection is Oceanic. Although the science vs religion debate is far from a new theme, it remains fertile ground for thought-provoking SF. Oceanic deals with the nature of faith and does it in a poignant way. Although science eventually proves to be the more compelling belief system for the young protagonist, it's done without malice and without smugness. It's a wonderful story. For me, the Amalgam stories were less engaging, though still fascinating enough to have me looking forward to the new novel. Egan's reputation for intelligent, ultra-hard SF with a philosophical edge will be enhanced by this new collection. For lovers of literary SF that stretches the imagination, it's a must. And you don't have to be physicist or a mathematician to appreciate them. If, like me, you're unschooled in these disciplines, Egan will help you to get your head around some pretty mind-bending concepts without dumbing them down or blinding you with science. That's quite a feat. And Egan is quite a writer!