How dare they do this to me? I had never been violent! Never! Had I? Of course, obviously, yes, ha, I had been extremely violent in my earlier life as a famously inventive ultra-assassin, but that was a long time and far far away and in another set of bodies entirely. (p.309)
I've got halfway through this novel several times, so finishing it felt like an accomplishment. I honestly don't know what made me stall: it's fun, pacy and often thought-provoking. It is also, despite the lack of author's middle initial -- at least in the UK edition -- very definitely science fiction.
There are multiple narrative voices, although not as many as you might think. Patient 8262 is an inmate in what seems to be a mental asylum: he isn't fluent in the local language, and spends much of his time reflecting on his past. The Philosopher reflects on his past as a torturer (first amateur, then professional). Madame d'Ortolan is the de facto head of The Concern (a.k.a. L'Expedience) whose purpose, according to the party line, is 'to make the many worlds better'. Mrs Mulverhill is a renegade Concern operative who's uncovered what she believes to be a massive conspiracy that will change everything. Adrian Cubbish is a London wideboy, a City fixer who got out of the coke trade and into hedge funds while the getting was good. And the Transitionary, effectively the protagonist of the novel, is an OCD ninja body-swapping multiverse-surfing assassin and occasional 'imp of the benign', intervening in the lives of the unAware (those who are ignorant of the multiple realities) for good or, usually, ill.
Not all the characters are likeable. In fact, they're all unlikeable to a greater or lesser extent. The Transitionary is not the only character with a misogynist mindset. It's not always clear who (if anyone) holds the moral high ground. Conversely, it's pretty obvious that the opening sentence could be spoken by any of the narrative voices:
Apparently I am what is known as an Unreliable Narrator, though of course if you believe everything you're told you deserve whatever you get. (p. 1)
At its heart Transition is a story about whether the means justify the end. There's a discussion of whether torture can ever be morally right. (When it saves lives? When it unlocks a mental barrier in the subject? When the victim is unaware?) There's a parallel thread concerning how power corrupts, especially when there's no consequence for misuse. (Dictatorships, limited companies, withholding knowledge for the greater good).
I'm not wholly convinced by the ending, which has a deus ex machina feel to it. There are a couple of other points in the novel where I felt a key piece of information had been deliberately withheld (that restriction on the minds a Transitionary can enter, for instance): and there are plot elements that seemed to be left unresolved (the attack in the asylum; Mrs M's eyes). And the whole conspiracy seems ... not exactly inconsequential, but rickety. Transition, though, is a sprawling novel with multiple threads and a non-linear structure, so it's not impossible that a rereading would knit the story together more firmly in my mind.
Reading this, I was reminded of two classic short stories: Connie Willis's 'And Come From Miles Around' and Robert Silverberg's 'Passengers'. The former seems a template for the film that a character's trying to pitch; the latter could be an examination of the sleazy underside of the Transitionary's uber-cool world-walking.