The new Iain Banks book, Transition, is a science fiction novel. This is despite the fact that it is not published as by Iain M Banks.

And I don’t mean the slightly-ambiguous, could-be-a-dream-or-somebody’s-madness-if-you-don’t-want-to-suspend-your-disbelief sort of thing you get in The Bridge Or Walking On Glass, either. This is out-and-out SF, no queries or discussion. It is a tale of parallel universes, of an infinity of alternative Earths, and of people who can move between them, using a combination of drugs and native ability.

And it’s that ability that holds both one of the novel’s unanswered moral questions, and its biggest flaw.

When adepts transition between the worlds, they do so in mind only. That is, their mind occupies - possesses - the body of someone who already exists on the target parallel.

Ethically, this is a minefield, of course. But that question is only vaguely touched on.

Other ethical issues are addressed, notably the use of torture by states. There is passing character - just a walk-on, really - of a policeman who once tortured a terrorist suspect and had some success. He was tortured in turn by his guilt for the rest of his life.

The big flaw, though, concerns the transition mechanism and its use, and to talk about it, I’ll have to include some minor spoilers. So, you know: you have been warned.

As I said, flitting between the parallel universes involves the mind, the personality of the transitionary jumping into the body of someone already existing on the target parallel. This applies even when someone takes a ‘passenger’ along, which some can do. Each of them takes over a body in the new world.

But sometimes Banks has characters jumping to places where there really couldn’t be a body for them to take over (versions of the Earth that are uninhabited, for example). Yet they seem to jump successfully.

I don’t mind there being a ‘bodiless’ and a ‘bodiful’ version of the ability, for example: but it does need to be explained, or at least mentioned. I can hardly believe that nobody picked this up in the revision and editing process.

That aside, though, it’s damn fine, and probably his best ‘non-M’ for quite a few years.

With the secret cabal that is trying to run the world(s) behind the scenes, it is sort of The Business 2.0. Or maybe 10.0.