This is a smug and self-regarding book full of smug and self-regarding characters. What reviewers seem to classify as intelligent literature is incredibly condescending, a very linear plot encased in high-falutin' words and popsci anecdotes.
The plot is pure painting-by-numbers. I'm happy to start doling out spoilers, as it may save others from reading this book. The theme: Madness. So, let's have our main character, Joe, apparently go mad. If he's going to go mad, we best make sure he's a nice rational scientist to start off with. But him going mad is too obvious, so let's have it only look like he's gone mad, and actually it's the other guy, Jed, going mad. Reveal 'twist' at end. If he's going to be proper mad, let's make him a full-on 'Jesus nutter', to contrast with our atheist scientist lead. We need a subplot, so let's add someone else having suspicions of an affair, which turn out to be nothing. That's about it, really.
So, the characters. Joe and Clarissa are two-dimensional upper-middle-class North Londoners who would pretty much make me happy to nuke North London, even if where I'm sitting is on the edge of the blast zone. They're hollow shells of characters, with a relationship sufficiently brittle that they apparently neither understand nor can communicate with each other after seven years. The only rationale for most of their actions appears to be to further the plot. This failure to animate their relationship is what really kills the believability of the plot.
Outside the central stereotype of upper-middle-class North Londoners, and the occasional Oxbridge academic, we fall to caricature remarkably quickly. The Disreputable Criminal Types from which Joe obtains his gun deserve some kind of award.
However, I really think Joe deserves the most attention. He's the central character of this book. This seems to mean he's going to have an interest in picnics in the Chilterns with specific white wines and lumps of mozzarella, and generally act suspiciously like a well-regarded novelist. Obviously he must be literate, in order to have the voice given to him in the novel. He's got to be A Scientist, but he can't be too alien. So, he's a freelance science writer. To make him A Scientist, we'll give him a PhD in QED, rather than just letting him be a journalist with some science mates. And then show his scientific prowess by littering the novel with bite-size pop science nuggets. Perhaps the author knows an entirely different breed of physicist PhD to those I've met, but I can't escape the feeling that the author just ain't that good at creating characters.
Plot: sucks. Relationships: suck. Characters: suck. But this isn't the end! This novel takes itself far too seriously, and shows off to the reader at every opportunity, without challenging them in any way. It seems to want to say 'Can't I tell a marvellous story?', utterly unaware of the fact that it can't, and that far less 'worthy' books can both spin a better yarn, and challenge the reader a whole lot more.