Rating: 4/5
Verdict: Popcorn meets profound in mind-bending sci-fi thriller

A prediction: The market demand for mind-altering substances is about to take a dive.

For, once Inception takes hold at the cinema - and it surely will - this movie will have its attendees happily dazed for days, possibly weeks, afterwards.

As M.C. Escher, whose famous infinite loop drawings are the basis for many a baffling scene in Inception, once said: "I don't use drugs, my dreams are frightening enough."

Obviously, so too are those of director Christopher Nolan. What he does with the stuff of dreams in Inception makes it both brilliant and initially baffling. But its mental maze soon proves readily navigable and - apart from some flat spots mostly brought on by some plodding exposition - captivates for its lengthy duration.

This marks the return to the mind-bending style of his all-original earlier works like Memento and The Prestige. With Leonardo DiCaprio up front and a hefty US$160 million ($224 million) budget, it's also Nolan's next big-star blockbuster after his second Batman flick, Dark Knight.

DiCaprio is top mental secrets burglar Dom Cobb. He's found a way of networking into the dreams of very important people to steal their secrets.

We first meet him in the dream of Japanese industrialist Mr Saito (Ken Wantanabe), a sort of test run for a mission Saito needs done - to install an idea into the head of the heir (Cillian Murphy) to a rival energy conglomerate.

That reverse engineering of the mission means Cobb and his sidekick Arthur (Joseph Gordon-Levitt) must assemble a new team. The recruits include newbie Ariadne (Ellen Page) as the "architect" whose job it is to create the dreamworld from scratch - and to keep asking questions on behalf of the audience.

And there's Eames (Tom Hardy) who has a talent for disguising himself as people the dreamers know. But that's just the half of it.

Cobb's own mind is distracted by his late wife Mal (an alluring Marion Cotillard), whose memory he keeps trapped in his head but which risks acting as a virus on the team's neural network.

Why he's the only one whose personal issues affect his work isn't explained. And the rules for how things work in the various levels of dreamworld might seem, at times, a little too flexible.

But at least Nolan's mental twilight zones don't default to hallucinogenic ambiguity.

Sure, Paris becoming its own skyline is impressively surreal, but the worlds of Inception are elegant studies in architecture and maths and beautifully bendy physics, which neatly enhance some of the action scenes.

Sometimes though it's just good old blazing guns, like the sequence in a snowbound military complex which looks like it was inspired by any number of shoot' em up videogames or Alistair MacLean commando novels.

But that all takes place within Inception's biggest riddle - that there might be dreams-within-dreams. And that how time elapses between the different dreams can really do your head in when you wake up in the real world.

How Nolan and his editors juggle between those multiple narratives running on different clocks and keep this trucking along to its climax is one of the major reasons Inception remains so engaging all the way to its note-perfect ending.

Its elaborate mental games do mean that the main emotional element, Cobb's grief for Mal, doesn't really have a chance to resonate, no matter how much DiCaprio is at pains to express his anguish.

But even if it favours head over heart, Inception is still affecting in other ways and profoundly entertaining.

Cast: Leonardo DiCaprio, Joseph Gordon-Levitt, Ellen Page, Tom Hardy, Ken Watanabe, Marion Cotillard
Director: Christopher Nolan
Rating: M (medium-level violence)
Running Time: 150 mins