Here's the concept: A new technology enables people to go to sleep and actively participate in one another's dreams. You can probably think of a few different applications for such a technology, but the movie Inception focuses on just one: Corporate spies use it to get inside the minds of executives from rival firms and root around in search of valuable secrets they can steal.

The action begins with two such data thieves, Dom (Leonardo DiCaprio) and Arthur (Joseph Gordon-Levitt) infiltrating an elegant party at the palatial seaside home of a high-rolling Japanese tycoon named Saito (Ken Watanabe).

It is quickly revealed that the mansion is literally Saito's dream house, and that Saito himself is aware the entire scene is taking place inside his head. Arthur wants to abort the mission, but Dom insists on pressing forward--even after a mysterious interloper named Mal (Marion Cotillard) inserts herself into the scene.

Pandemonium ensues. Mal attempts sabotage, Saito calls in his paramilitary guards, and a tsunami bursts through the windows.

And that's one of the movie's less complicated scenes.

Dom and Arthur are criminals, but Saito, their intended victim, is not exactly an innocent lamb. Impressed by their efforts, he hires the duo to pull off their next caper in the cranium of a man named Fischer (Cillian Murphy), who has just inherited a business empire that Saito wants to smash.

Dom recruits a Mission Impossible-style team of amoral talents, including a master of disguise, a chemistry wiz and a brilliant young architect, who together cook up an elaborate scheme to get inside Fischer's dreaming head, and then take Fischer along with them to a dream within a dream, and then descend to a dream within that dream, and then...

Inception is a brilliantly constructed puzzle that demands an enjoyable degree of mental work to keep up with what is happening on each level and how it all fits together. Despite its complexity, the film does a superb job of first laying out all of its rules--mostly as Dom explains them to the newly recruited architect (Ellen Page, who played the title role in Juno)--and then finding logical ways for those rules to be broken.

Inception was written and directed by Christopher Nolan, who has a track record of twisty films, such as Memento, The Prestige and The Dark Knight.

The intricacy of the events, and their visually appealing presentation, provide more than enough entertainment to make Inception a must-see, but that is pretty much all the movie offers.

The characters are fleshed out only as much as the plot requires, and they don't offer anyone to care about or seriously root for. There's not much to Inception beyond its basic concept.

But what a concept.

The movie opens today.

(Jul. 23, 2010)