To go into the cinema knowing next to nothing about a film is a rare thing indeed these days; even rarer if the film in question is one of the biggest of the year, both in length and cost (148 minutes and $200 million respectively), with a huge cast of familiar and, in general, really really ridiculously good-looking stars. Yet though Inception is perhaps the summer’s most anticipated film, hardly any plot details have been available in the run-up to its release. The trailers have been cryptic, the posters more so, while the writer/director Christopher Nolan has refused to reveal anything remotely resembling a spoiler in interviews, smiling that he likes to ‘keep things a little close to the chest.’ Such extraordinary secrecy is with very good reason – not only does it ensure that the film itself is a surprise (and an extraordinary one at that), but the plot is so ambitious, so utterly balls-to-the-wall ridiculous, that any attempt to explain it would send you laughing from the room. At the risk of sounding like a tagline, it needs to be seen to be believed.

As such, there is little alternative for this review to be anything other than ambiguous – perhaps frustratingly so. Nevertheless, to provide a plot synopsis would be to do a severe injustice to the film itself, so, to put it in the vaguest possible terms: Inception centres on dreams and their connection with reality. This initial concept is one that allows for seemingly limitless invention from Nolan, and he embraces this with one of the most ambitious and complex scripts in recent years, piling on twists and complications from the first frame to the last. Such complexity is a hugely risky endeavour, as at any point there is the possibility that the film might lose the audience completely, and it is to Nolan’s credit that we never feel too perplexed. Indeed, he seems to have an innate trust of, and respect for, his audience, and never slows the plot down to make sure everyone’s keeping up (though Ellen Page’s Ariadne is perhaps a little too blatant in her role as a surrogate audience, there to have the plot explained to her). It’s intensely cerebral, and insists that the viewer keeps their wits about them. However, the film is by no means a dry or academic affair, and while it explores fascinating ideas and themes, it never skimps on the spectacle. Inception contains some truly groundbreaking action scenes, including a gravity-defying fist-fight similar (though superior) to those in The Matrix and an epic climax at a snowy mountain base, reminiscent of Bond at his best.

Indeed, Christopher Nolan rams his film full of cinematic, literary and artistic references – from Greek mythology to 2001: A Space Odyssey, M. C. Escher to Edith Piaf – and seems happy to acknowledge the debt this film owes to others. Perhaps most unexpected are the similarities that Inception bears to both Charlie Kaufman’s Synecdoche, New York and Scorsese’s recent Shutter Island; indeed, Leonardo DiCaprio’s role in the latter is remarkably similar to his role here, though Nolan has coaxed a marginally superior performance from him. He is effortlessly stylish yet internally fractured as Dom Cobb, a father just trying to get back to his children, and it is in his hands that the film becomes more than just a hyper-intelligent action flick. A common complaint of Nolan’s films is that they lack emotion, with a coldness reminiscent of Kubrick, yet while such a comparison is, in many ways, highly complementary, it falls down with Inception. One of the crucial reasons this film is Nolan’s best is because, while he has retained his tendency to produce a carefully calibrated and precisely engineered film, he has finally embraced the more raw, emotional punch his previous work lacked. Thanks both to his script and the powerful performances of DiCaprio and Marion Cotillard, the film becomes a surprisingly and gratifyingly moving experience.

If nothing else, Inception will go down as one of the riskiest endeavours ever undertaken by a filmmaker. Fresh off the record-breaking success of The Dark Knight, Nolan became the golden child at Warner Brothers, and was finally allowed to develop what had been his dream project (in more ways than one). Yet it could so easily have all fallen apart, collapsing into a self-indulgent, incoherent vanity project under a director drunk on success. Happily, nothing could be further from the truth. That the ideas behind the film have obsessed him since he was sixteen says a lot for their complexity and, more importantly, their quality, and the decades he has spent developing the script have clearly paid off. Challenging and often surreal ideas are presented far more clearly than they might have been, as Nolan consistently displays a steady-handed grip on the material. The audience is never allowed to be too bewildered, and much of the credit for this must also go to the editor, Lee Smith, whose ability to find coherence amongst the four simultaneous set-pieces at the film’s climax is nothing short of a miracle.

Inception is outstanding in almost every way conceivable, from Hans Zimmer’s brutally dramatic and modern score to Wally Pfister’s magnificent cinematography, which makes the most of the astonishing and hugely varied locations that the film travels to. No-one makes a false step amongst the ensemble cast, all of whom deliver fantastic work, with Cillian Murphy and Tom Hardy proving particularly impressive. Ultimately, however, this is Nolan’s film, having written and directed it with apparently limitless creative freedom. The world can finally have unfiltered access to his vision, and it’s like nothing we’ve ever seen. Although it owes huge debts to a vast number of different films and works of art, and though it even embraces genre to some extent – it is, in many ways, a heist film, though by no means a conventional one – the greatest and most striking virtue of Inception is its fierce originality. It functions at once as a superior thriller and a self-referential tribute to the infinite possibilities that face a true artist. Against all odds, and in a summer of well over twenty remakes and sequels, Christopher Nolan has delivered a phenomenal action film of extraordinary intelligence. There aren’t enough superlatives in the world.