On this evidence Nicholas Royle is a man with a fertile imagination. And no one is about to read his book and accuse him of a lack of ambition. No discipline, perhaps. No idea how to end a novel, certainly, but hardly a lack of ambition.

Evidence: you think you have this allusive tale licked within just a few pages. We are in contemporary London (oh, how the heart sinks at the sound of those words) and privy to the private thoughts of Chris. He's a young man who likes young man things -- music, driving, friends like Max, and London.

Each section of the book is prefaced with the medical definition of a constituent of the heart. Chris is inclined to romanticise his city like that. And Royle has latched onto that particular over-romanticised organ -- in both its physical and metaphorical incarnations -- as the hub of his tale. Then there's the ruin of an old hospital to which Max's friend Danny is strangely attracted. And when it's reclaimed as a luxury hotel, the site of Max's other pal Charlie's heart attack.

Didn't we say ambitious? Because that hospital -- that room -- long, long ago also played host to the world's first heart transplant.

All of which is marvellous stuff, to be sure. Royle juggles multiple time-frames and styles like a master. There's the vaguely overheated Victorian melodrama of George Maddox's medical experiments, the laddish cars'n'girls stuff of young men about town, and the emotional tour-de-force of Chris' father's death that necessarily grounds Royle's more fanciful flights.

The problems -- you just knew this was coming -- begin on leaving London. There's a brief, inconclusive stop-over in New Orleans before we touch down in Australia. Chris is here for Joanna, the cardiologist he met whilst hospital-visiting Charlie. And it's when she abruptly vanishes that Royle attempts to up a gear into mythical, noir territory -- with mixed results.

The last third of The Matter of The Heart, after the disappearance (itself brilliantly written, incidentally), has the feel of an author in search of his plot. Characters wander panicked but aimless up and down desert highways. It's ill-focused, even confusing, and seeks unsuccessfully to suddenly cast the thus far unseen Danny as a black-hearted villain. The snag is that, with nothing to base him on, his arrival in the narrative is baffling. Here's where you begin to appreciate why road stories make better movies than novels. The end is brusque and, given our emotional investment, frustrating.

This is a clever, often exceptionally well written book that recalls the chatty, nimble-footed plotiness of Jonathan Coe. And it's some testament to Royle's skill that you care enough to want to know what happens. It's just that when you care this much, you cannot help but be disappointed by such a perfunctory pay-off.