Here's what you're not getting. A traditional, three-act autobiography that places some contemporary situation in the first chapter to lure you in, before falling firmly into a strict chronological narrative, detailing the formative years of arguably Britain's most famous film critic. Perhaps the picture of a man clutching popcorn and a chainsaw should give that away, though.

Instead, what you get is pretty much the written movie version of Mark Kermode's life. He's utterly open about this, even casting the whole movie for you, naturally enough drafting in Jason Isaacs to play himself. And, once he's set himself within this framework, Kermode explores - with due confessions that his memory isn't great - the moments that got him to where he is today, and how they've been wrapped around and been influenced by the films that he's seen.

What's more, it's a set-up that works far better than it should. It helps enormously that Kermode has very clearly written the book himself: the voice and style of his radio broadcasts comes across loud and clear in the written word. That also means you get the same digressions, the same humour and the same celebrations of films that you don't hear too many other critics championing. The same love of Julian Sands, too. It's a fairly safe bet that if you don't warm to Kermode on the radio, then you're not going to warm to this book at all.

But if you do, then It's Only A Movie is a treat. And while there's inevitably and rightly diverting talk about films themselves - The Exorcist, as you might expect, isn't bereft of attention (and the story of his meeting Linda Blair for an interview is a warm one), but then neither is Slade In Flame - it's the situations that Kermode has got himself into that deliver the book's gold.

The most gripping, as it turns out, is the tale of a trip across Russia and the Ukraine on the trail of a small horror movie. Considering that the journey Kermode describes sounds both hellish and deathly dull, it's a very, very funny account he tells. Likewise, he and Werner Herzog being shot at can't have been much fun, but the version of the tale in the book is both very well told and hard not to smile at. If you're looking for the comedy highlight, though, then it's worth turning to the segment where Helen Mirren tackled Kermode regarding his review of The Queen. It's a brief, but golden, section of the book, and a beautifully structured telling of the tale.

The smaller stories come across just as well, from Kermode's first fumbled broadcast, through to blagging his way into an unsuccessful stint doing the listings for Time Out. And interspersed with all of that are enough little threads and nuggets to constantly keep things interesting and moving along. Plus, like all good film books of this ilk, there's a to-watch list that develops as you make your way through it.

The off-centre style that Kermode adopts isn't going to appeal to all, and it's arguably the non-film specific moments where It's Only A Movie is at its finest. But the book is nonetheless a witty, engaging and successful collection of anecdotes, stories and asides, delivered in a very personal and engaging way.

It's a very, very good read, and you finding yourself wishing by the end for Mr Isaacs to get on with the job of learning his lines...

It's Only a Movie: Reel Life Adventures Of A Film Obsessive is out now and available from the Den Of Geek Store.