In the land of Haspide, a devoted and charismatic woman doctor ministers to both the poor and the mighty, eventually gaining a loyal supporter in the phlegmatic king. Across the continent, meanwhile, a bodyguard named DeWar lives every moment of his life trying to protect a rather cruel liege-lord who intends to establish a new empire of his own. Because the Culture seems to suffer from some deeply conflicting notions about how much it should interfere in the development of primitive civilisations, both DeWar and the doctor spend most of their time doing nothing. Which leaves lots of time left over for the planet's various political conflicts to be described during elaborate courtly balls and political debates. One could easily excuse such passages if they managed to evoke a truly alien culture, but the closest Banks comes to clarity in this novel is to pour a lot of consonants on the page and then shake.
Inversions likewise sets out to play a game with readerly expectations.
At the same time, though, Banks's rehashing of SF tropes seems almost contemptuous of a genre which demands, if nothing else, a genuine respect for the clarity of pure storytelling. With many memorable books under his belt, it's hard to understand how Banks could write one as unsuccessful as this. Iain M Banks is a sci-fi nerd.