Cloud Atlas by David Mitchell

How economical is the structure of David Mitchell's Cloud Atlas? When the author confessed at the Guardian book club event at the Hay festival that his novel had once been intended to have not six but nine sections, a member of the audience suggested that this left room for a sequel. Or, responded Mitchell, there could be a "director's cut" version. As we laughed at the expense of movie-makers' self-importance, he observed that this was not entirely a joke: it had indeed been suggested that he include "excised scenes" from the novel in an ebook version of Cloud Atlas. Mitchell is a virtuoso of literary pastiche (his article in this paper last week listed the authors and styles that he imitated). One commentator on the book club website thought this mere technique: "by the halfway point it felt as though I was reading the output of a series of creative writing tutorials, each asking the writer to demonstrate competence in a different genre". Mitchell's admirers, however, delight in what one called his "ventriloquism" – his "multitude of tones and styles" – and like to feel there is hardly a limit to it.

Opinion is divided about how testing Mitchell's structure of nested narratives really is. One reader at Hay called Cloud Atlas the "natural successor" to the "relentless experimentation of meta-fiction" characteristic of post-modernism. A reader on the website thought the experimentalism was bluff: "He's a genius at making middlebrow readers feel that they're experiencing the avant garde." But this could also be said in admiration of the novel. "I really don't know where its reputation as being 'demanding' came from as I think that does it a disservice – it's a bit like the best-ever volume of Reader's Digest Compacted Library – and I don't mean that in a bad way." This reader, like many, thought that Cloud Atlas used structural trickery to satisfy old-fashioned narrative appetite. "Each cliffhanger and new voice ratcheted up the tension for me. The pay off was that once they started collapsing back into each other again all that energy came back out in the most glorious fashion."

Mitchell himself spoke at Hay of his impatience with the kinds of "meta-fiction" that keep reminding the reader that he or she is reading fiction. He must be glad to know that some of his readers think of him as, in the words of one, "a real storyteller in a literary world which abandoned storytelling some time ago". As a website reader remarked: "If you go on to the London Underground and look at what your fellow commuters are reading, you will see plenty of Twilight and Stieg Larsson, but you will often catch people reading Cloud Atlas with the same enthusiasm. I've seen three this week. Who says the literary novel is dying?"

On the book club website, readers undertook some close analysis of the relations between the novel's different narratives. There was some resistance to its use of the comet-shaped birthmark given to several of the main characters. "If we do take it at face value – that all these characters are reincarnations of one another with unconscious recollection of the previous life to theirs and who learn of that previous life's history – how does it embellish the story in any way? This irks me because it detracts from the (truly successful) thematic connection between the stories." Another responded that "the transhistorical connections – the 'Cloud Atlas' melody, the birthmark, the text of each protagonist 'folded into' the hand of the next (in time)" did not indicate "actual reincarnation", but suggested that the novel's "drama of amity and destruction" was "connected through time historically – materially and culturally, in artefacts and institutions".

One critically attentive reader worried about the fact that Adam Ewing's journal (narrative one) and Robert Frobisher's letters to Rufus Sixsmith (narrative two) give way to the story of Luisa Rey (narrative three), which is revealed by Timothy Cavendish (in narrative four) to be a novel. "Frobisher describes Ewing's book in his letters to his friend Sixsmith, who then shows up as an old man in the third narrative. Which means that if, within bounds of the novel, Luisa Rey exists only in a work of fiction written in Cavendish's time . . . then the first and second stories – including Ewing and Frobisher and Sixsmith too – must be fictional as well, as they are part of the same fictional construct as Luisa Rey".

Is this a logical glitch? "Not necessarily," replied another reader. "I could write a fictional account of a 17th-century nobleman who studies the Domesday book – my book would be fiction, but the Domesday book exists in reality." Everyone seemed to agree that Cloud Atlas was a novel that rewards analysis – or as one reader sardonically put it, it is "just the sort of book most critics wish they'd written". Perhaps this means that it is a novel written by an author who loves stories, but also knows plenty about criticism.

John Mullan is professor of English at University College London. Next week he will be looking at American Psycho by Bret Easton Ellis. Join them for a discussion on 14 July at 7pm, Hall One, Kings Place, 90 York Way, London N1. Tickets are £9.50 online (www.kingsplace.co.uk) or £11.50 from the box office: 020 7520 1490.