Bought brand new a couple of years back, as I was really impressed with the first Culture novel. Haven't read yet, so looking forward to reading the whole series together.

This is an excellent adventure story, although anyone not used to reading hard SF might struggle with a lot of the technical issues that it deals with. A mysterious sphere has appeared where an artifact one did millenia ago, and the Culture need to know what it is. Genar-Hofoen is pulled out of his diplomatic post and sent on a desperate race to find the only person to have seen the original artifact, someone who only exists inside a ships computer system. But, as usual, nothing is like it seems. He has a personal issue that needs to be dealt with, while behind everyone's backs a group of sentient machines are plotting a little war of their own to deal with a more tangible enemy. And the sphere just sits there.

This is a great read, but can be a bit confusing, especially when the ships are 'speaking' to each other. The romantic attachments of Genar are quite revealing and surprising, bringing a little bit of light relief until the truth darkens it all again. A bit disappointing that the sphere's agenda isn't really found out by the end of the book.