I have to admit I found this a strange book. The prose is so transparent, so lacking in artifice, as to render the narrative curiously flat; the opening and closing sentences, in particular, are almost toneless. There is no 'style' (barely any description; barely an adjective in the entire book); the authorial voice is more conspicuously absent than in almost anything else I've ever read. Yet the dialogue is brilliant, and as a 'thriller' - of sorts - it's utterly compelling. I read it not just on the Tube, but on the escalators; not just on the bus, but in the bus shelter. The lack of 'voice' makes the main character (it's told in the first person) hard to both know, and sympathise with; yet this is, I suspect, entirely deliberate; the readers' perception is being played with all the time, and that would be made harder if the narrattee was someone whose side you were firmly on. Yet for all that - for all the skill doubtlessly employed in its creation - there is something missing, something more than what was designed to be missing. I'm finding it hard to put my finger on what. Perhaps it is, quite simply, heart.