The worlds of writer/director Christopher Nolan and science-fiction author Phillip K. Dick blend seamlessly in "Inception," a cerebral summer entertainment that will almost assuredly require multiple viewings to pick up on all its careful details and clever asides. (The film's not actually based on a Dick novel, but the author's influence bursts through every confused, layered, mind-bending sequence.) The story of a brilliant but troubled thief who invades the minds of his marks via a process called "group dreaming," "Inception" combines pretty much every film genre into one tangled, complex, provocative 160-minute experience. It's a well-executed caper, an over-the-top action film, a trippy science-fiction fantasy, a brooding romance, a psychological thriller and even, at times, a far-out comedy. All Nolan really needed was a cowboy and a hockey game and he'd have every category of American filmmaking represented.If all that sounds like a recipe for an overcrowded film, well...it is. And part of me thinks that this is actually a far superior screenplay than it is a film. But at the same time, the intensity of the viewing experience, the excitement of seeing so many brilliant ideas brought together and the polish that Nolan and his more-than-capable crew (particularly cinematographer Wally Pfister, composer Hans Zimmer and editor Lee Smith) bring to the material completely won me over. This is destined to be the most ingenious, and quite possibly the most entertaining, film of summer 2010. (Which is really saying something, as "Toy Story 3" was significantly ingenious and entertaining.)The aforementioned thief is Cobb (Leonardo DiCaprio), the world's foremost expert on group dreaming who has been using his skills at invading people's dreams to steal corporate secrets for profit, a process known as Extraction. That is, when he's not being haunted by visions of his mysteriously absent wife (Marion Cotillard) and the children he left behind in America. Cobb is then approached by a Japanese energy tycoon, Saito (Ken Watanabe), who asks him to use his team and abilities for a far more complex task than Extraction. Saito needs his main corporate rival, Robert Fischer (Cillian Murphy), to make a business decision running contrary to his own financial interest, and wants Cobb to "plant" this idea in Fischer's head. This is known as Inception (hey, that's the title!), and most in the field of group dreaming (a surprisingly large field, now that I think of it) consider to be impossible. This sets the stage for the 'heist' storyline I alluded to earlier - in which Cobb must assemble a team to design and execute a layered dream for Fischer that will lead to the executive changing his mind about the direction of his company - and it also leads to the film's extended conclusion, in which the inception must actually be carried out. This is a complicated idea, and Nolan somehow manages to continually make it more complex and demanding, while keeping everything fairly brisk and relatively easy to follow. I wasn't 100% certain I always knew exactly what was going on in every moment of the film, but I rarely found myself having to go back and "get my bearings." The dream Cobb and his crew design for Fischer involves 3 different "levels" - an initial stage in a rainy city, a deeper dream set in a large hotel, and a final sequence set in a snow-capped mountain fortress - and Nolan cleverly allows the sets and costumes to visually cue us to which portion of the dream we're currently viewing. The layered dream conceit also allows for the film's best action sequences, in which the physics of one dream level (such as a van in which the characters are sleeping plummets off of a bridge) impacts the physics of the next dream level (causing people running down a hotel hallway to suddenly fly up into the air). To avoid spoilers, I can't fully articulate the inventiveness of Nolan's screenplay, one of the most intricate pieces of writing I've seen brought to the big screen in years. (Nolan surely only got the budget to make this movie because he is Nolan.) There's a lot of talking and exposition in the movie, which I know has turned off some reviewers, but the ideas here are so fascinating and so well-established and considered, it really didn't bother me. Take a sequence in which Cobb and his new "dream architect," Ariadne (Ellen Page), discuss the nature of the tactile world of dreams while sitting at an outdoor cafe. It takes a bit of chatter just to explain all the concepts that Nolan needs to get across in this scene - what it means to "create" the world of a dream, who these people are that are populating the dream world, what happens when someone is injured or dies in a dream, and so forth - but the dialogue itself is advancing our understanding of things we've already seen, and it all builds to a visually dazzling sequence in which the dream world itself begins to collapse. (This is a recurring motif in the movie - dreams crumbling and imploding on themselves - that's in some ways reminiscent of Alex Proyas' similarly-brilliant "Dark City" from 1998). It's heady and takes a while to get everything across, but it's nonetheless compelling, and there is a certain amount of brevity and efficiency in the explanations. Nolan doesn't take the time to tell us about anything he doesn't bring back later in the film for dramatic effect. And even when the film is just two characters talking, there's a lot to love about "Inception." Hans Zimmer's score, for starters, is completely captivating, exquisitely framing both the unthinkable scale and the underlying sadness of Cobb's day-to-day life. It's his best work in years. The cinematography by Wally Pfister (Nolan's collaborator on the similarly beautiful "Prestige" and the Batman movies) is simultaneously elaborate and stark. The "dream worlds" are each given their own personalities, but there's also a gray, claustrophobic urbanity that runs through the entire film, as if Cobb is stuck in an endless, inescapable city, with unknowable secrets hiding behind every door. The effects work is also tremendous, and surprisingly subtle, considering this is a movie in which city streets fold in on themselves and skyscrapers crumbling in the background become an expected, almost quotidian, sight. The sound design also warrants mention. Part of the conceit behind entering and exiting dream states in the film has to do with repetition. Hearing dialogue and sound from reality will often jar people out of dreams, and small noises like the breaking of a wine glass or the spinning of a top take on great significance within the movie. All of this is handled delicately and with an attention to small observations that's unexpected from a big summer entertainment of this size. Having said all of that...the final "inception" scenes tended to feel a bit long-winded, particularly in terms of the action. Putting together an effective action sequence has always been Nolan's Achilles Heel. (My one fault with his two "Batman" films is that the action never quite lives up to the visual flair of the movies around them.) He fares better here, and at least 2 of the action scenes here - a foot chase through the streets of Mumbai and the fistfight down the zero-gravity hotel hallways I mentioned before - are among the movie's highlights. But there's an awful lot of random punching and gunplay as the inception wears on (largely used to break up scenes of expository dialogue down the stretch), and it feels a bit unnecessary. The movie starts to drag a bit just as it should be picking up steam. Though we're always clear, as viewers, on which level of the dream we are seeing at any time, we're jumping between dreams so frequently that it tends to kill the tension of the shootouts or car chases. (How can you stay involved with a car chase if you're only seeing 2 out of every 10 minutes of that chase? That's one kind of action set piece you can't really "pick up" in the middle.) There's so much that's great about "Inception," I feel like this is something of a minor quibble. Still, it's a 160 minute movie that probably would have been tighter as a 140 minute movie. And delightful as Tom Hardy is as Cobb's "forger" (and the film's comic relief), I don't really need to see him take out 30 dream soldiers when 10 would have done just as well. "Inception" feels both like a natural extension of the major themes that have dominated Nolan's films up until this point - particularly in how it explores the subjective, even fraudulent, nature of what we perceive as "reality" - and a major step forward for him in terms of scope. If he wasn't already on the list, it ranks him among the most significant, interesting Hollywood directors of the moment. And though it's only July, I predict this will EASILY be the best, most imaginative screenplay we'll see brought to the cinemas this year, if not necessarily the best overall movie.