Meshes of the multiplex: "Inception"

Here's a challenge for you: go see Christopher Nolan's Inception - and you really should, as it's liable to stand as the smartest of this summer's major releases - and try and make head or tail of the opening thirty minutes. Okay, so we ascertain that Leonardo diCaprio's hero is in the middle of conning a Japanese businessman (Ken Watanabe) by entering into his elaborately designed headspace and stripmining his dreams for the relevant info - but it turns out everybody's dreaming here, and that we're as likely to wake up on a bullet train speeding through downtown Tokyo as we are in a cityscape that merges elements of New York and Paris. Not for the first time in a frenetically edited contemporary blockbuster, we know not where we are; in Inception, however, that sense of spatial bewilderment appears a deliberate tactic.

Still, one might ask, what kind of directorial sensibility spends this much of a studio's money on something as wilfully avant-garde as Maya Deren's Meshes of the Afternoon? The same who gave the world Memento, perhaps - the American cinema's first movie-in-reverse - or indeed who dares to call a summer event picture Inception, with its absence of reassuring been-there-done-that suffix. As signalled by the lack of plot spoilers emerging this once from the Hollywood dream factory, Nolan's film is intended as one giant leap into the unknown: by the end of the film, we find ourselves up a mountain in China, although such is Inception's ambiguity, its fragile layering of realities, we may also just be climbing the walls of somebody's cranium.

It's my intention here not to explain that paradox, or give too much of anything else away, but it may help viewers struggling through that opening salvo to consider Inception as a post-post-modern reboot of The Matrix - another summer event that invited us to question how much of our lives, our dreams, our thoughts are our own - after a decade in which issues of identity and copyright theft have become paramount. In a near-future, diCaprio's fugitive scientist Dom Cobb raids dreams in a form of nocturnal industrial espionage, and in this - as it seems in all endeavours - the Japanese are at the forefront. Having himself been duped in the prologue, Watanabe's Saito has hired Cobb's crew to turn deception into inception, not removing but implanting a single thought ("I will split up my father's empire") inside the head of a rival mogul's weak-minded heir (Cillian Murphy).

The methodology is conveyed simply and effectively by Cobb's right-hand man (Joseph Gordon-Levitt): "When I say to you 'Don't think about elephants', what's the first thing you think of?" Well, pachyderms, quite possibly. The ultra-cineliterate Nolan takes the opportunity to implant (or draw out) movie memories of his own: Inception begins, like the Spanish mnemo-thriller Novo, with its hero awakening on a beach with no knowledge of how he got there; the use of Edith Piaf's "Je Ne Regrette Rien" as a wake-up call seems to connect with the casting of Marion Cotillard as Cobb's estranged wife; and indeed the whole subplot involving diCaprio attempting to process his wife's disappearance feels like psychic slippage from the recent Shutter Island, a film delayed so long in transit Nolan couldn't possibly have seen it - unless he himself had entered Martin Scorsese's dreams.

The set-up is also the excuse for much digitally-enhanced peacocking. While entering the dream of a gifted Sorbonne student (Ellen Page, nicely grounded in an otherwise thankless, tagalong role), Cobb proceeds to flip the top half of Paris up and over onto its lower boulevards, as though Montmartre were no more than the retractable roof on a convertible. One of the few elements I admired about the laborious and pedantic The Dark Knight was this director's bold use of architectural space, a facility granted fuller rein here: Page is recruited as a mental software engineer, to construct the mazes that provide each dream's underlying structure, there are doll's houses that rhyme with actual houses built in a city of the mind, and a pleasing wrinkle during a chase scene, as Cobb diverts into an alleyway only to see it narrow to the point where he risks getting stuck.

The suspicion remains that Nolan is better with concrete and concepts than he is with flesh and blood, however. Inception is an undoubted improvement on the Batman movies, lacking in humanity as they were: thanks to diCaprio's most convincing performance in some while, we sense that Cobb has pursued his profession to hold onto fading memories of his loved ones, and that he accepts the Japan gig in a bid to be reunited with his two young children. Still, there's not too much else in the way of tenderness evident here. Cotillard, all wild eyes, is cast as the crazy Frenchie getting her nails into our hero; she could be the teenage Nolan's abiding memory of Betty Blue, 25 years on. (We know the couple's relationship isn't likely to end well when her Mal - geddit? - starts holding dear to sharp knives.)

Even when Inception maps out Paris, the immortal city of love, the dreams Nolan weaves concern buildings exploding and crashing down around the dreamers; elsewhere, they involve characters being hit by speeding juggernauts. Who has these kinds of dreams, we might wonder, save stressed filmmakers rushing to hit their deadlines for a studio's summer release strategy? (And wouldn't it be cheaper to prescribe them Xanax, rather than a $200million budget?) I can't help but think that, as an ideas man, Nolan might have been better served by the more modest means typically accorded to the likes of Andrew Niccol (Gattaca) or Vincenzo Natali (whose 2002 thriller Cypher this sometimes resembles) - but then the colossal success of The Dark Knight appears to have inflated everything that has followed in its wake.

There's little doubt that Inception is overworked pulp at 149 minutes; a B-movie like 1990's Brain Dead - the Bill Pullman/Bill Paxton one, not the Peter Jackson one - romped through many of these mental-appropriation ideas with a similar cleverness, but at half the length. By the final 40 minutes of Inception, with its myriad corridors beginning to spin like tumble dryers, a spectacular incoherence - the kind that, in faithful symmetry with the opening, again leaves us unable to tell up from down - has set in, and we spot that while Nolan is good with individual spaces, he's less certain bringing them all together. (Consider the stand-off on the passenger ferry towards the end of The Dark Knight: a technical masterclass, granted, yet a sequence utterly apart from the rest of the film.)

It would be churlish to carp at an event movie that speaks in terms of "specificity", "catharsis" and "animosity"; that seeks to turn on a particular turn of phrase ("I was disappointed that you tried"); it is, at the very least, a polysyllabic blockbuster, and in the summer of the grunting The Losers, we might well be happy for that. Yet too often Inception feels as though it's being held back by a tendency to blow all its dazzling original ideas up - to render them projectile, in the audience's face! - rather than nailing them down, or exploring them in any real depth. (As he did during the IMAX-ready The Dark Knight, Nolan can appear more concerned with height, or breadth.) All we're left with are fragments of greatness, echoes of brilliance, a dream within a dream within the biggest marketing budget of the season.

Inception is on general release from today.