Life without Rebus was never going to be easy, which is probably why the eight CDs of Rankin's latest novel have been sitting on my bookshelf unloved and unheard. By the way, Orion's new stacking audio cases are so much more practical than those impossible plastic boxes with their flimsy dividers - but doesn't stacking naked CDs damage them, and if not, why didn't someone think of packaging them like this years ago? Fearing the worst, I steel myself and start listening. My first reaction is that having the same reader, James Macpherson, whose gritty voice I now associate exclusively with Rankin's sleuth, and what sounds suspiciously like the same bluesy intro music isn't a good idea. Who is this DI Ransom? Where is DI Rebus? And then gradually, like switching from petrol to LPG, nothing matters except the ride - and this new Rankin ride, still around Edinburgh but from a slightly different, non-cop perspective, is brilliant.

Bored, art-loving software entrepreneur Mike McKenzie decides to spice up his life a little by masterminding a thoroughly civilised heist at the National Galleries of Scotland. It's not quite new lamps for old, more fakes in exchange for 19th-century Scottish colourists, which, if all goes to plan, will result in each of his fellow plotters - a banker, a professor and an art student with a talent for forgery - ending up with a genuine masterpiece. But what starts as a game turns into a nightmare involving the criminal underworld and a quasi-Viking psychopath with HATE tattooed across the knuckles of his left hand. And his right. It's fast, violent and edgy, with an ending maybe even Rankin didn't intend, because it's left to Macpherson to identify, by selecting which of his many voices to use, the avenger knocking at the door. How's that for a twist?

For a really successful novelist, there can be few scarier things than writing your first book after killing off a long, vastly popular series. After Aubrey-Maturin, where next? Harry Potter's pensioned off before he needs hair restorer, but does that leave his globally famous creator anywhere to go? Different authors have different solutions. Patrick O'Brian died just before his series ended, which was characteristically shrewd, if a little extreme. Some authors change tack or invent a new hero/heroine/fantasy world.

After 20 years Ian Rankin, onlie begetter of Rebus, seems barely to have paused before charging straight back to the keyboard. He appears not even to have had the common decency to go through a mid-life crisis and disappear for a year to drink himself silly. Instead he's produced a new thriller with new characters, and only familiar geography to reassure the fan.

Brave man. For this is not quite the Edinburgh of Rebus. The unforgettably self-hating, chewed-up-and-spitting-out Scottish detective, slouching with hangover groans through shades of American film noir and shadows of Stevenson and Hogg, carried his city around with him. He was dry enough to make sardony a word and sucked the sunlight out of Scotland's capital. The Edinburgh of Rankin's new novel also has its skirt of pebble-dashed, scummy menace, its forgotten council schemes, piss-stained billiard halls and awesomely violent thugs. But it seems a touch more balanced without that half-mad, grey-and-liver-coloured face glaring back at it.

The story starts with a far lighter touch, too. Three men dream up the perfect art heist. One is a computer millionaire, retired early with his toys and now bored. One is a grouchy professor of art. One is a nervous banker who feels life is passing him by. There's an almost John Buchan mood: three chaps settling down for a final big adventure, egging one another on as they knock back their drams. Their scheme is both simple and clever; I won't give it away. Yet I felt slightly disappointed.

The feeling quickly passed. One of the problems of a long and successful series, whether it's about sailors or child magicians or detectives, is that eventually the characters and the setting start to overwhelm the narrative. What Rankin has done is to free himself from the detail and murk that a Rebus devotee would expect, and to plunge into pure, fast storytelling. Here, barely a sentence, indeed barely a syllable, is wasted. The characterisation is as much as the narrative needs and no more - a couple of facts, physical traits or jokes so that the reader remembers who's who, and then on with the tale.

Because Rankin is a master storyteller, that means the reader is quickly swept up and carried along. I read this in one sitting, on a swelteringly hot beach in Greece; I kept meaning to do other things - find a beer, fetch a sunhat, check the BlackBerry - but somehow had to keep putting them off until I finished this chapter; and then the next; until I'd reached the end.

By then, I'm glad to report, the genteel Edinburgh of the amateur art thieves had collapsed into a gory spiral of loutish menace, violence and mayhem. It was a good idea to set a story in the Edinburgh art world: it is rich, introverted and hasn't, to my knowledge, been skewered before. Those who know their Scottish painting will enjoy visualising that early 20th-century painter "Monboddo" - a bit Cadell, a whiff of Fergusson too - and the works of that lugubrious Victorian portrayer of cold sheep, "Utterson". There are jokes about painters as various as Jack Vettriano and Banksy.

The final third of the novel is a heart-pounding and relentless rumble as our heroes find their options running out, and the reader wonders, a little late, who the heroes really are. Light social satire gives way to fear and fists. Again, I will give nothing away - except to say that for anyone toying with the idea of crime as a form of boredom therapy, this story is not, on balance, an encouragement. Assuming you're still allowed to smoke in hell, even Rebus will spend a happy hour or two with Doors Open.

· Andrew Marr's most recent book is A History of Modern Britain (Pan)