When I blogged Surface Detail, I complained that Banks was getting caught with mission creep. Having set Consider Phlebas around the edges of a galactic war that characters in The Hydrogen Sonata are still talking about a thousand years later, he was making it harder to top the fireworks in the various Culture books which came after it. It continues to be my view that the best of the Culture books is the deeply creepy Use of Weapons, which is all about a nice manageable local mess and the damage it does. But no-one ever listens to me, and Banks went on dialling it up, with Surface Detail tackling heaven and hell, having mined out reality some time back.
For his last SF book, and a book which he must have known would be his last book, he took another swing at the afterlife, trying to set a book in and around the last days of a civilisation which is "Subliming". In most of the Culture books, there have been passing references to Subliming, as something which civilisations do when they've exhausted reality's potential and move to an ethereal plane, never to be heard from again. This must have seemed like a fitting capper to his career, an apposite note to go out on. I suspect that it went off the road pretty early on when he realised that the moment you describe the indescribable, you've ruined it. So instead, the Gzilt civilisation's move to the ethereal plane is basically a big shiny backdrop to a pretty routine saga of political skulduggery and AI chicanery, both well trodden areas for Banks.
One of the minor paradoxes for me in enjoying all those Culture books is that while I love the idea of his vast, effortlessly canny ships with their unbeatable Minds, once he slings more than two or three of them into the action they start to blur into one another no matter how much effort he puts into the funny names for them. In The Hydrogen Sonata, Mistake Not… would have been plenty of Ship all on its own, but it's just one of dozens, and more is not more when you're chucking well-nigh invulnerable dei ex machina at the page.
In a way, The Hydrogen Sonata is a retread of Consider Phlebas; against a backdrop of something huge and complicated, one kinda-human is off on a scavenger hunt for a secret which might change everything. Or might not. It's a perfectly serviceable plot, but it's not anything like the best that Banks can do. It's also kind of a stupid way to engage with the theme I think he really was going after. The whole point of Sublimation, as it's always been explained in the past, is that the civilisation in question has risen above the material and short-sighted day to day nonsense we all live with, and is ready for something else. But there's a whole political chicanery sub-plot involving the Francis Urquhart of the Gzilt and his beavering away to cut deals on the eve of a phase-change which will render all the deals completely pointless. Something doesn't make sense here; either these guys are ready for the infinite and beyond such pettiness, or they're not, in which case why is the infinite even on the agenda? It's never properly teased out. The irony of a man making pointless deals because it's all he knows how to do - there's book in that, but this book isn't it.
Banks was starting to lose his edge (or I was starting to want different things from my fiction) as he got older, and I knew that this was a book where he wouldn't have been at this best; he simply didn't have the time to get it right. So I didn't expect this to be a magnificent send-off for a mighty talent. I expected it to fizzle a bit, and still to enjoy it on the back of the really good ones from years before. What upsets me is not so much that I'm disappointed in the book, but my feeling that as he got to the end of it, Banks himself must have been feeling disappointed. Facing into the end (with his waspish humour more than intact; he announced his fatal cancer by saying he'd asked his girlfriend to do him the honour of becoming his widow), he must have wanted The Hydrogen Sonata to say something striking about tranquility in the face of extinction, and the value of a life lived to make a difference in the here and now (I'm not guessing; Banks has always been pretty clear about not believing in an afterlife). I wish it had been a better book, not for me, but for him.