Something has gone wrong with mobile phones. People who use mobile phones are turning into crazed zombies who are attacking everyone else. And there's an awful lot of people who use mobile phones. Including our main protagonists son. Can he reach him before he switches it on? Think Dawn of The Dead, only crossed with those 'Orange Wednesdays' adverts you see at the cinema. Except done better.

I started reading this book twice. The first time I picked it up, I found myself thinking that Stephen King, whom I've always regarded as a great storyteller, had decided to go straight for the viscera as a shock tactic, and it made me wonder if I actually wanted to read on.

The first time, I just put the book down. When I did pick it up again and get past the opening scenes however, I realised that I had been wrong and the story - and as usual Stephen King's marvellous characters - drew me in. To some extent it's another one of his 'road trip' books: look at The Talisman, at The Stand, and at several others to see the characters who have been stuck together in adverse circumstances and are trying to get to a particular destination.

I'm not trying to say that it's formulaic, merely that there are only a certain number of things that you can actually have the characters do. While I was actually reading the book, I certainly wasn't offering up any comparisons. I was just reading the story. It's only afterwards that I can play with it and compare it to other works.

So you get drawn into the characters quickly, which is good. You develop a liking for them, which is good. You're never quite sure which - if any - are going to make it through to the end of the book, which is good. When reading some books you just know that they're all going to make it out the other side, with others you're hanging on to the last page waiting to find out.

It sucks you in, it rattles you along, and it spits you out the other side 512 pages later leaving you wanting more. I can't fault that too much. All the same, it's not the best book I've read - not even the best Stephen King book I've read; but it's plain to see that he's a storyteller with a great deal of skill in his craft.

I bought up this book for no other reason than I had an hour to kill, and nothing to read, so I thought I might as well get a new book to start reading.

I'd never come across Gerald Seymour before, but from the blurb on the back, I got the impression that the book was some kind of crime/action thriller, which I'd say was a pretty fair assessment.

It begins quite slowly, setting the scene and introducing the characters. The main character, Malachy Kitchen (nice name) seems a little difficult to like at first, but you soon start to get hints of his troubled past (which the blurb on the back has told you about anyway).

His troubled past is as an army officer in Iraq, where he is accused of cowardice in the face of the enemy. He leaves the army and sinks. By the time we encounter him at the start of the book, he is living on the streets. Soon Malachy is given somewhere to live - a flat in a tower block on a virtually lawless estate where the residents are in fear of the drug users and pushers, where he continued to reject completely any contact with society, save for an infrequent cup of tea shared with his elderly neighbour.

When his elderly neighbour is mugged by a drug user and ends up in hospital, this presents an opportunity for Malachy to climb back on the ladder towards self-respect, and he begins his crusade…

There is a lot of changing between different characters who are introduced. This has both advantages and disadvantages: the advantage is that the characters who Malachy (and others) encounter are fully rounded and fleshed out and you understand their motives; the disadvantage is that it makes the narrative flow a little jumpy.

That's a minor quibble though, as the narrative that is there is clear and understandable for all of the characters. After a slow, building start, the action builds up and there's some good use of narrative tension: one encounter builds up and you're trying to guess what is being planned and then it cuts to the aftermath of what's happened.

It sounds out, but it's almost as if the writer has an eye for cinematography: the way in which this is done would work perfectly in a film and - perhaps surprisingly - works very well in a book too. In some respects it was slightly disappointing because you could see what the writer was capable, and some passages were exquisitely well written, but in some others I found my attention drifting away, and that's not a good sign.

At 576 pages, I think that the book could probably have been made tighter, and I felt the story would have been better served without the tying up of loose ends after the climax, as I felt by that point it just felt that the narrative was winding down and the author was looking for a way out.

I can't say it's the best book I've ever read, but it didn't get interrupted by any other books - and as I've normally got about three on the go at any one time, that's pretty good going. If you like action/crime thrillers, you'll probably like it. If you don't, you probably won't.

Despite my intial preconceptions that this would be a dark, dreary gloomy book, it proved very difficult to put down, following me around the house - front room to kitchen, to bathroom, to bedside table - until I'd finished it.

To be fair, it was a dark and gloomy book, I'll make no bones about that, but it wasn't dreary.

The Kevin of the title is the narrator's son, who "did a Columbine" and killed lots of people in his school, and the chapters of the book are a series of letters his mother writes to his father, looking back at his upbringing. You know you're jumping directly into this from the beginning, as the back of the book tells you, so you've got ample opportunity to avoid it if you don't like the subject matter.

Kevin isn't a very lovable character, and I found myself wishing that someone he'd encountered much earlier would have had the decency to bump him off at some earlier point: ideally with his parents, as I didn't become particularly attached to them either.

So, despite all this, why am I rating it as a 4?

Because while the subject matter may be gloomy and depressing, it makes you ask questions about yourself, and your relationships with your parents and your children. Because it gets under your skin, drawing you forward towards what you suspect is probably coming but you know you're going to have to face it anyway…

It's extremely well written, and as soon as you ask yourself the big "what if" question, it goes from being a work of fiction to something much more powerful - a survivor's manual. Not the manual of a survivor of a massacre, a manual of the equally wounded animal - the family of the kid that did it. The family whose name is now synonymous with mass murder.

How would you cope? Could you cope? Could you bear to go shopping in the same supermarkets, watching the parents of children your son murdered push their trolleys around the same supermarket? Can you bear to watch Eva try to pull the shattered pieces of her life back together after that Thursday? I couldn't bring myself to look away…

I'd not choose this as a holiday book. I like upbeat, frothy things for that, which this plainly isn't.

As a work of literature, it's one I'd recommend. If you like thought-provoking, sometimes harrowing novels, this will suit you down to the ground. It's the literary equivalent of a Ken Loach film. It's like Bournville chocolate: dark, powerful, and while you know not everyone is going to like it, some will love it.

But I'm still not entirely sure why the high-school slaughter had to be set on my birthday…