I Am China looks as though it is going to be a simple, even classical love story.

Jian is a fiery alternative musician in China. Having become notorious as a political gadfly, he's expelled from the country. From detention centres around the world he exchanges letters with his girlfriend Mu, an altogether more hard-headed and practical poet. Their correspondence supposedly forms a debate about China, artistic freedom, love and individuality. Jian, wishing to be a firebrand, loses his liberty, of course; Mu is more flexible and remains in the world.

Then there's Iona, a slightly unsure translator of Chinese in London. She's from Scotland, which we are told is cold, rather like herself. When she gets bored with translating, which is often, she likes to have anonymous sex, which we have to watch. A handsome publisher straight out of Mills and Boon, and one of the most astonishingly wooden, implausible characters you will ever encounter, gives her a sheaf of documents he's acquired - the letters and diaries of Jian and Mu. He doesn't speak Chinese, but he thinks there may be something compelling in there somewhere. Iona must sift these scraps to see if she can find, or forge, their narrative. It takes her an amazingly long time, and the reader is unwillingly drawn in to the same process, the same doubt: is this a story?

Jian quickly ceases to be a viable character, as he's under arrest most of the time. There's a good point made about the nomenclature governments use for the "non-persons" of this world: he's in a "removal" centre, then in "detention", then "protection" (as he rightly wonders, protection from whom?). The novel could be about dissidents and the "detained", but detention centres are all pretty much the same, and it doesn't make for much drama. Jian loses interest in writing, coming up with stuff like: "The artist looks down at his cock, and his cock looks at his guitar. Then his guitar looks at him. They all look at each other. Who is playing whom? Each said: 'I am!'" As he's bounced around the globe his correspondence with Mu becomes patchy; their belief in each other wanes.

And this is the problem with this novel: having Iona paw through this bundle of stuff, which she never appears to assess or even put in order, the power and the eloquence of Mu and Jian's work and thoughts are lost. There is a story, but it's not helped by stopping and starting (the idea being, possibly, to add a fast-cutting, "cinematic" energy). There's a constant, inelegant repetition of what we've been told, implying we need to be reminded of things - when in fact the plot was so simple it didn't need to be hacked up like this in the first place. The diaries and letters, atomised as they are, remain inchoate to Iona, and to us.

There's a stubborn opacity to the prose, which is strewn not with incident but with what the author plainly believes to be emotional triggers, though they come across as Tin Pan Alley cliches. Dead baby? Flowers? Snow falls on an apple tree in the garden of the silly publisher? So? And it's unfair - it's torture, in fact - to be intricately told what it's like to scroll up and down in a document on a computer screen, and to be expected to find suspense in that.

Mu's story is the best the novel has to offer, the only story that takes place before our eyes - everything else is maddeningly hidden, reported; off-stage. But we've gone through quite a bit in order to watch the only fully-realised character, a revolutionary poet, get a running-dog's office job in London, the very heart of late capitalism, just as Mr Fancy Pants Publisher caves in to Chinese government coercion like a wet noodle. It doesn't always seem right to turn a book against itself, but after so much wheel-spinning and cruel dangling of plot points and forced coincidences, Jian dies just minutes before Iona, moved as she was by his plight, was to meet him. "It cannot be!" she exclaims. "Oh f***." My sentiments exactly.