Evil Ted told me to re-read this one. He may be right: it may be the best of the Culture novels. It's extremely well constructed. The main character's struggles highlight everything that the Culture seems to have given up: struggle, challenge, the savor of a battle narrowly won, the bitter taste of powerlessness. And their willingness to use him to their ends highlights their hypocrisy.

It's hard to not loathe the Culture by the end of the book. The perspective of a non-Culture citizen working as a Culture agent gives us more of an insight into their base morality than that of an adversary (Consider Phlebas), or an ordinary Culture citizen (Player of Games). If the Culture is "A tiny core of Special Circumstances, a shell of Contact, and a vast chaotic ecosphere of everything else", then the core is as thoroughly ruthless as its agents.