LAURENT Binet's first novel won the Prix Goncourt du Premier Roman, but the question a clodhopping reader like me will tend to ask, even before the question of its prize-worthiness comes up, is: is it a novel at all? It doesn't seem to be sure. "If this were a novel," we're told in chapter 211, "I would have absolutely no need for Valcik (a minor character in the story)." Then chapter 205 consists, in its entirety, of the declaration: "I think I'm beginning to understand. What I'm writing is an infranovel."

The occasion for HHhH - that is, the story it makes such heavy weather of turning into a book - is the botched-but-ultimately-successful assassination of Reinhard Heydrich, the Nazi viceroy in occupied Czechoslovakia (as it was) and senior architect of the Final Solution. HHhH, incidentally, is the abbreviated expression of the saying, "Himmlers Hirn heisst Heydrich" - "Himmler's brain is called Heydrich". The Czech government-in-exile in London conceived Operation Anthropoid, a two-man commando team - one Czech, one Slovak - that parachuted into the protectorate and ambushed Heydrich's Mercedes as it made its way through the streets of Prague.

Confronted with a subject as portentous and as over-described as Nazism, writers seem to jump one of two ways. Either you decide that the only way to see these events afresh is to radically defamiliarise them with the violence of imagination. Or, like HHhH, you jump the other way and regard fiction as betrayal, a "glib falsification". So this "infranovel", at least ostensibly, is fastidious in its refusal to make anything up. Occasionally, Binet will write a scene, then haughtily disavow it, scolding himself that it simply didn't happen that way. He frets at some length about whether Heydrich's Mercedes was black or, as some accounts have it, dark green. He regrets not knowing what colour suit Göring wore on such and such an occasion.

But rather than dispose of his methodological anxieties in a brisk paragraph early on and proceed with putting together his narrative, the story is all about the putting together of the narrative. So what this is, probably, is a novel about someone trying to write a historical novel. The narrator - let's call him Laurent Binet for the sake of convenience - is the actual fictional character; a slyly demented author-narrator.

We learn that Binet is self-righteous and a little sentimental (he's full of huff and puff about the cowardice and hypocrisy of Neville Chamberlain), that he's more than a bit obsessive about his story, and that the Prague of then and the Prague of now coalesce in his mind.

Early on, he has a dream about writing the "scene of scenes" and including the phrase, "A black Mercedes slid along the road like a snake". About 200 pages later only the tense has changed: "A black Mercedes is sliding along the road like a snake." The snake gives way to a different image: "Feel the wind of history as it begins, gently, to blow." Then another: "In the narrowing flow of this story, those five are about to reach the waterfall." Not long after, "Heydrich's Mercedes snakes along the thread of its knotted destiny" - which I guess is either a clumsy translation or an intentionally funny ineptitude.

Anyway, after a lot of solemn metafictional/infrafictional hand-wringing while Heydrich's back story is put in place, the plot proper gets going and things take a pleasingly thrillerish turn. And it really is a remarkable story, immersively realised in the closing sections of the book. For many readers this will be what saves HHhH from being ZZzZ, but I doubt that's what won him the Goncourt.

Early on, Binet tells us: "I never thought of giving (the story) any other title than Operation Anthropoid (and if that's not the title you see on the cover, you will know that I gave in to the demands of my publisher, who didn't like it: too SF, too Robert Ludlum, apparently)." So either the publisher's marketing department won, or the whole thing's a big put-on. It's that sort of book: clever, occasionally funny, a little bloodless, and self-regarding in the fullest sense of the term.

©2012 The Financial Times Limited

TITLE: HHhH

AUTHOR: Laurent Binet, translated by Sam Taylor

PUBLISHER: Harvill Secker