David Mitchell's much-hyped (Booker-tipped, even) Cloud Atlas is a novel about society, and about power. Other words you could throw around to describe its themes are civilisation, predation, oppression, and conflict. Big words, and big themes - this is not a shy work. It is, however, exactly the sort of novel you would expect from someone who's written a thesis on `layers of reality in the postmodern novel.' It somehow avoids being intimidating, however - Cloud Atlas is always an straightforward, exciting read, never a pretentious or forced one. It is smart without being obscure. It is easy to like. And it is precisely 34.03% science fiction.

I can say that with such accuracy thanks to the book's structure. It's a Russian doll of narrative: six novellas in all, arranged so that story F, in the novel's centre, is bracketed by the start and end of story E, which is bracketed similarly by story D is bracketed by C...and so on, all the way out. As the reader encounters them, the tales run up a track of historical and linguistic change from `The Pacific Journal of Adam Ewing' (1850, or thereabouts) to `Sloosha's Crossin' an' Ev'rythin' After' (date unknown, but at least a few hundred years into the future); then they run down again on the other side. In Mitchell's hands, this structure is much more than a gimmick. Not only is it the main expression of the previously mentioned postmodernism, as each narrator in turn discovers the testimony of his or her predecessor, but it's the main reason the thing is so damn easy to read. I'll say it again: The book is composed of six novellas. That means that although it's a big read, you're almost always reading a beginning, or some important plot advancement, or an ending. There's no slack.

Unsurprisingly, the science fiction was the heart of the novel for me; Mitchell's skill with a first-person narrative is truly remarkable, but when combined with some thoroughly satisfying worldbuilding I found the results spectacular. He offers two futures. The first, `An Orison of Sonmi-451' is a brave no logo world, a retail dystopia in which clones are conditioned as a servile underclass. Sonmi-451, in fact, works in the local fast-food joint. The second, `Sloosha's Crossin'...' is a post-apocalyptic fable rich with the shadows of John Wyndham and Walter M Miller, Jr. Make no mistake, these are pulp futures of the old school - but they are none the less effective for that.

The six testimonials of Cloud Atlas make dark reading. They tell of a humanity with a will to power, and they suggest a bitter historical inevitability. Make no mistake that, although it ends on a note of hope, this is a dark novel. It is also, however, an almost entirely successful one - frustratingly so if you were hoping the hype was, well, hype. I can well believe this might make the Booker shortlist; in fact, I would be pleased to see it there. And it could even, in my eyes, make (whisper it) a Clarke nominee in 2005. Hey, if Quicksilver can make the cut, why not?