The latest (2000) book from Iain M. Banks, before he takes a years holiday from writing.

It deals with the results of Culture interference that went horribly wrong, and also contains some threads from Consider Phlebas, as the light from two suns that were detonated by the Idirans in the Twin Novae battle reaches the Orbital where much of the book takes place.

In typical Banks style, the book also covers a number of other themes, such as reaction to the loss of a loved one (human or otherwise), caste systems, and more.