The Thousand Autumns of Jacob de Zoet by David Mitchell

David Mitchell, of Cloud Atlas (2004) rather than Peep Show renown, has become a big name in the 11 years since his first book, winning prizes, attracting admiring reviews and finding a large, cultish readership. But even after four substantial novels – one of them, Black Swan Green (2006), semi-autobiographical – it's hard to get a sense of his artistic personality. Style and, despite some recurring interests, themes don't have much bearing on his authorial signature, which has to do with more diffuse devices: multiple narrators and narrative modes, a wide range of settings in time and space, wispy connections within and between his books. A lot of his writing takes the form of pastiche, and he's equally wide-ranging in the writers and genres he "does": Haruki Murakami, airport thrillers, Melville, science fiction. Does he have a vision and voice of his own, or is he more of a mashup artist, a maker of structurally ingenious page-turners? In full flow, he makes the pages turn sufficiently smoothly to make such questions seem churlish as well as simple-minded.

It's clear, however, that Mitchell has a problem when it comes to sustaining a straight narrative without benefit of channel-flicking. His most distinctive books artfully reshuffle smaller units – short stories in Ghostwritten (1999), novellas in Cloud Atlas – in ways that let him jump playfully between tones and genres, holding the whole performance together by means of thematic linkages and Short Cuts or Pulp Fiction-like overlaps between episodes. His first novel built around a single spine of story, number9dream (2001), seemed to reach a bit nervously for a heavy armature of subplots and alternative realities. Black Swan Green, though more restrained, was a consciously episodic, story-sequence-like novel which overdid the 1980s period detail and struggled to find an appropriate level for the voice of its 13-year-old narrator. But Mitchell, who isn't lacking in artistic ambition, hasn't flinched from another stab at non-gimmickry in his new book, a sprawling and, at first sight, conventional historical novel.

The Thousand Autumns of Jacob de Zoet begins in 1799 in Nagasaki, where a Dutch trading post on the man-made island of Dejima is Edo Japan's sole point of contact with the European powers overrunning the rest of the world. Only the highest Dutch officials are permitted to cross the bridge to the mainland; the Japanese authorities closely monitor their subjects' interactions with the Europeans, and under the shogunate's policy of seclusion, it's a capital crime for any Japanese person to leave the country. Into this claustrophobic situation comes De Zoet, a young Dutch clerk who's been packed off to the east to make his fortune by a prospective father-in-law. A straight-arrowish, mildly priggish type, De Zoet arrives as a protégé of the trading post's new boss, who announces that he aims to stamp out corruption. In consequence, the clerk has a hostile reception from the existing assortment of grizzled European traders as he feels his way into the island's exotic social set-up.

Unknown to most of the ground-level actors in this highly formalised encounter between civilizations, both sides are also grappling with historic changes. The Dutch East Indies Company is in a bad way, thanks partly to British naval harassment, and the Dutch haven't told their Japanese hosts about a revolution in Holland. In Nagasaki, meanwhile, a rising merchant class is chafing against its feudal constraints and absorbing western innovations in warfare, science and political economy. De Zoet, who owns a copy of Adam Smith's The Wealth of Nations, which greatly impresses a friendly Japanese interpreter, seems destined to get involved in controversial, perhaps transformative exchanges. Few of his Dutch confreres share his intellectual interests, but one exception is Dr Marinus, the trading post's grumpy resident physician. A thoroughgoing Enlightenment man, Marinus teaches medicine to selected Japanese students, among them a young midwife with a burn-scarred yet beautiful face. Her name is Orito Aibagawa, and after a couple of fleeting encounters De Zoet predictably falls in love with her.

The first third of the book lays all this out in a painstaking fashion, and appears to set the stage for a searching novel of ideas and political intrigue. But it's hampered by Mitchell's clumsy handling of third-person narration, which he's rarely used before, and a feeling that he's too busy with the story's architecture to pay much attention to the words on the page. Often these don't mean quite what they're meant to: "Hatless and broiling in his blue dress-coat, Jacob de Zoet's thoughts are ten months in the past . . ." And Mitchell has made some eccentric stylistic choices. Nearly every line of dialogue is broken by action doubling as a speech tag – "'Who was that bizarre female,' van Cleef squeezes a lemon into a Venetian glass, 'in Warehouse Doorn?'" – and there are lashings of ye olde-tyme talk and salty seadog-speak. Anachronisms also weaken the spell cast by Mitchell's research: Marinus, for example, quotes "Kubla Khan", not published until 1816, and mentions "Shangri-La", from a novel of 1933.

At the end of the opening section, however, the novel springs a number of narrative surprises, switching channels without leaving the network it's established. With De Zoet, now disgraced, still stuck on Dejima, the point of view shifts to the Japanese characters – principally Orito and the friendly interpreter, Uzaemon, who turns out to be in love with her too. The reader gets filled in on affairs in Nagasaki, where impoverished samurai are falling prey to moneylenders. But the main action is of a completely different order. On the instructions of a previously minor figure, Abbot Enomoto, who seems to have supernatural powers, Orito is secluded in a remote temple compound, a place of unspeakable horrors with shades of Murakami, Margaret Atwood and Ursula K Le Guin. Once Uzaemon starts plotting a rescue, events among the Dutch are more or less forgotten in a welter of escape attempts, ninja assaults and such resoundingly Marvel Comics-like villainous utterances as "Why do you mortal gnats suppose that your incredulity matters?"

Not surprisingly, the third and final section, in which the arrival of a British warship throws Nagasaki into chaos, has difficulties putting all this material into some kind of all-embracing frame. Mitchell opens out the story still further by adopting numerous points of view, and there's no denying the imaginative energy he brings to his maximalist project. The "hidden Christians" left over from the 17th century in Japan, the enslavement by the Dutch of non-European peoples, the far-reaching consequences of the French revolution and the emergence of a global commercial system: all these and more find their way into a story that's already packed with oriental fantasies and carefully worked historical details. But the final effect is confused.

The main problem seems to be that Mitchell hasn't decided if he's writing a straight historical novel, a grandly themed fable or a cheerfully trashy romp. Or rather that he's decided to write all three, but without a structure robust and flexible enough to keep the different elements in balance. The basic premise – a colonial-type cultural encounter in one of the few non-European countries that fended off the colonial powers – is a good one. But much of the thematic-looking stuff, such as the repeated images of seclusion and enclosure, turns out to be little more than structural gaffer tape, and more substantive matters are handled simplistically. The European Enlightenment, for example, is served up in two flavours: good, associated with botany and sound midwifery practices, and bad, associated with predatory lending and guns. With one or two exceptions, the characters fall into goodies and baddies as well, and their doings – including the central love story – don't often rise above the needs of the plot.

All the same, it's hard not to warm to the fluency and copiousness of Mitchell's yarn-spinning. Even – or especially – at his silliest, he keeps the pages turning, effortlessly throwing out each character's back story, setting up cliffhangers and moments of pathos, and, when it's necessary, summoning Abbot Enomoto to kill butterflies by telepathy. Mitchell has been under pressure for a while now to write something tastefully understated, even middle-of-the-road. Sensibly, and perhaps to his credit, he hasn't tried too hard to do so here.