Corporate espionage conducted in the deepest recesses of a target's subconscious is the subject of an imaginative, complex thriller from "Dark Knight" director Christopher Nolan. The Warner Brothers release was nominated for eight Academy Awards, including Best Picture, and won four Oscars.

By CBS News.com producer David Morgan

"I know how to search your mind and find your secrets."

Leonardo DiCaprio stars as Dom Cobb, whose career of corporate espionage takes him into the dreamscapes of his targets, where he is able to extract information from their subconscious. Shared dreaming, developed by the military, has for Cobb become an avenue to accessing others' secrets - but his subconscious poses threats of its own.

Cobb and his partner Arthur (Joseph Gordon-Levitt) engage in a shared dream with a Japanese businessman, Saito (Ken Watanabe), from whom they must steal secrets for their client, a Saito competitor. They speak as if they are selling their services to a potential customer, but we learn that Saito is actually auditioning them for a plan of his own.

We also discover that Cobb's subconscious projections and memories can invade and disrupt the dreamscape and pose serious threats, as when the spectre of Cobb's late wife, Mal (Marion Cotillard), appears.

Exiting (or escaping) a dream comes by way of a "kick" to the body, which awakens the subject. When Cobb is dropped into a bath, water itself invades his dreamscape even as he comes to.

Cobb has been in self-imposed exile from the United States after being accused in his wife's death. He is also on the run from corporate interests for whom espionage is a life-or-death matter.

Cobb receives an intriguing job offer from Saito, not for extraction but inception - inserting an idea into the target's subconscious to drive their behavior. Though told it cannot be done, Cobb knows otherwise.

His assignment: Enter the mind of the son of a dying business magnate. The intent is to inject the idea that Victor Fischer (Cillian Murphy) should break up his father's energy empire - Saito's direct competitor.

Cobb demands as his price for taking the job reentry into the U.S. to reunite with his children.

In Mombasa Cobb flees as corporate agents close in.

In Paris, Cobb is introduced to Ariadne (Ellen Page), an architecture student whom he tests for her ability to design labyrinthine mazes (in which to contain a target's subconscious projections). While dreaming, she also proves adept at manipulating environments.

During her introduction to shared dreaming, Ariadne discovers how physics and gravity in dreamscapes are manipulated, as she conjures a Paris that folds into itself.

Cobb assembles his team. In addition to Ariadne and Arthur are Yusuf (Dileep Rao), a chemist whose sedatives must enable the subjects to engage in several layers of dreams-within-dreams; Eames (Tom Hardy), a forger who can impersonate figures from a subject's subconscious; and, tagging along as a "tourist" (to ensure the success of the mission), Saito.

To gain access to Fischer's subconscious, the team arranges for the executive to share a 10-hour transoceanic flight. With sedatives applied, Cobb and his crew go to work . . .

. . . Only to discover that Fischer has undergone training by an extractor to defend himself against subconscious infiltration. Fischer's mind, Arthur declares, has been "militarized." While the armed security guards that confront Cobb's team are mere projections, their weapons seem very real - Saito is wounded.

Further jeopardizing the team are projections from Cobb's own subconscious (such as a rampaging freight train) which intrude into their shared dream world.

The stability of dream worlds is fragile - when one's body loses balance, the dream state loses its gravity. Time is also distorted.

This concept is brilliantly staged in a fight scene taking place within Arthur's dream - the corridor of his mind spinning as his body (actually, his dreaming body - this does get complicated) falls end-over-end in a toppling van.

Production Designer: Guy Hendrix Dyas
Special Visual Effects Supervisors: Chris Corbould, Paul Franklin
Stunt Coordinator: Tim Struthers
Editing: Lee Smith

In an even further level of dreams-within-dreams, Cobb leads Fischer into a mountain fortress in which is planted the seed of an idea that may - if Fischer's subconscious defenses do not stop it - redefine who he is and redirect the course of his life.

Fischer opens the vault, and faces a possible new destiny.

But while Fischer nears a buried secret, Cobb must confront the emotions that he has buried within himself. In an even deeper level of dreamscapes, he and Ariadne visit the world that Cobb and Mal had built for themselves. It is here that Cobb must learn to come to terms with his guilty feelings over Mal's death - and disassociate himself from the spectre that continues to stifle his future.

Inherent in Cobb's internal struggle are questions about the very nature of consciousness, free will and responsibility. How much are we to blame for our actions, and those of others? How do perceptions of reality differ from one person to another? And can memories ever be buried deeply enough for us to overcome the debilitating emotions they impose on us - or should they be?

The small totem that Cobb carries with him - a child's spinning top - is key to his understanding whether he exists in reality or in a dream state. But it also adds another layer of intrigue to "Inception"'s challenging story - its conclusion is contingent on whether Cobb will take a leap of faith, or delve even further into his own private heaven/hell.

Writer-director-producer Christopher Nolan studied English literature and filmmaking in London before shooting his first feature, "Following" (1998). But it was his time-shifting mystery "Memento" (2000) that put him on the map, earning Nolan an Oscar nomination for Best Original Screenplay (shared with his brother Jonathan) and a Best Director nomination from the Directors Guild of America. His later credits include the Al Pacino-Robin Williams thriller "Insomnia"; "The Prestige," starring Hugh Jackman and Christian Bale; and the 2005 reboot of the Batman franchise, "Batman Begins."

Despite its critical and popular success, "The Dark Knight" (the best film ever about a guy who dresses up as a bat and beats up people) failed to make the Academy's shortlist of Best Picture nominees, prompting derision - and a decision to expand the roster from 5 nominees to 10. ("I would not be telling you the truth if I said the words 'Dark Knight' did not come up" in discussions about the expansion, said then-Academy President Sidney Ganis.) More astonishment was expressed when Nolan - nominated by the Directors Guild - failed to receive a Best Director nomination for "Inception" (though he did receive nominations for Best Original Screenplay and Best Picture). Nolan is currently preparing the next "Batman" sequel, "The Dark Knight Rises," and is developing a new Superman film.

Rather than rely on computer-generated effects to convey shifts in gravity, Nolan wanted as much of the FX work done in-camera as possible. Taking a cue from Stanley Kubrick's "2001: A Space Odyssey" (in which rotating sets were created to depict weightlessness), sets were constructed in London that titled and spun. A 100-foot-long hotel corridor set (for Arthur's fight scenes) rotated 360 degrees, with practical lighting and remote-controlled cameras running on tracks underneath the floor. "I couldn't think of the floor being the floor and the ceiling being the ceiling," said Joseph Gordon-Levitt. "I had to think of it like, 'This is the ground. Okay, now this is the ground. And now, this is the ground.' It was just that the 'ground' was always moving under me. That was the mind game I had to play to make it work." A vertical version of the corridor was also built in which Gordon-Levitt was hung by wires. And the hotel bar set - also built to tilt 30 degrees - was padded and decorated with soft furniture in case cast members and stunt people fell over.

Cinematographer Wally Pfister shot "Inception" with a mixture of anamorphic 35mm, VistaVision and 65mm. The large-gauge formats and handheld cameras give the dreamscapes and action sequences a startling immediacy. Ultra-high-speed cameras (from 360 fps to 1,500 fps) were also used, such as in this scene when Cobb and Ariadne witness explosions decimating a Paris bistro and its surroundings.

A musical "kick" referenced in Nolan's script, Edith Piaf's "Non, Je Ne Regrette Rien" (ironic considering Cobb's many deeply-embedded regrets), was almost dropped when Marion Cotillard was hired, so as to avoid unwanted associations with her Oscar-winning performance as Piaf. But composer Hans Zimmer kept it, and wove his score around its notes, punctuations and meter, stretching out and electronically manipulating elements of the song to fashion a minimalist score filled with longing and astounding power. The music is accented by the guitar playing of Johnny Marr of The Smiths, which brings a haunting nostalgia to the work.

Click on the links below to hear samples from the score:
"The Dream Is Collapsing" Excerpt (mp3)
"Time" Excerpt (mp3)

Since his breakthrough in the 1993 film "This Boy's Life," Leonardo DiCaprio has grown to one of his generation's leading talents, nominated for three Academy Awards (as Best Supporting Actor for "What's Eating Gilbert Grape," and Best Actor for "The Aviator" and "Blood Diamond"). His other credits include "William Shakespeare's Romeo + Juliet," "Marvin's Room," "Catch Me If You Can," "Gangs of New York," "The Departed," "Revolutionary Road," and a little film called "Titanic." "Incepton" followed his deeply emotional performance in another head trip of a movie, Martin Scorsese's "Shutter Island."

Ken Watanabe received Academy Award and Golden Globe nominations for Best Supporting Actor for "The Last Samurai" (2003), and starred in Clint Eastwood's "Letters From Iwo Jima." He was also featured in "Memoirs of a Geisha," and Chrisopher Nolan's "Batman Begins."

French actress Marion Cotillard rose to international stardom playing Edith Piaf in "La Vie en Rose," for which she won the Oscar. She was the second woman to win Best Actress for a non-English langauge performance. Cotillard also appeared in "Big Fish," "Public Enemies" and "Nine."

Born in Nova Scotia, Ellen Page played in a variety of TV movies and series before starring in "Mouth to Mouth," "An American Crime" and "The Tracey Fragments," and playing Kitty Pryde/Shadowcat in "X Men: The Last Stand." Her big break was playing a pregnant teenager in "Juno" (2007), for which she was nominated for a Best Actress Oscar and received the Breakout Performance Award (Female) from the National Board of Review. Page appeared again opposite Cillian Murphy in the 2010 drama "Peacock."

Joseph Gordon-Levitt's acting began at age 7, with a variety of TV credits (such as "Murder She Wrote" and "Dark Shadows") and films ("A River Runs Through It"). He starred in the TV series "3rd Rock from the Sun." Other recent film credits include "(500) Days of Summer" and "G.I. Joe: The Rise of Cobra."

Tom Hardy plays Eames, a forger who can impersonate other people's projections within their subconscious. After his debut in the TV mini-series "Band of Brothers," Hardy gave an acclaimed lead performance in the drama "Bronson" as a prison inmate and his alter ego, Charles Bronson. Hardy's other credits include "Black Hawk Down," "Layer Cake," "RocknRolla," and TV's "Wuthering Heights."

Tom Berenger, who plays Fischer's confidant (and who appears as a shade of the forger's projection), starred in the 1986 Academy Award-winner "Platoon" (for which he received an Oscar nomination and a Golden Globe as Best Supporting Actor). His other credits include "The Dogs of War," "Major League," "Gettysburg" and "Training Day."

Best Cinematography winner Wally Pfister told reporters that the reason he was even nominated was because of his director, whose films he'd shot since "Memento." "There's no way I accomplish what I've accomplished without the brilliant vision of Chris Nolan," Pfister said."

He also rejected 3D technology (some scenes of "Inception" had been converted from 2D but those tests were abandoned). "I'm personally not a big 3D fan. It doesn't really work for me. I don't like the glasses, I don't like the dark image . . . It feels a little gimmicky to me."

As did several other craftspeople, Pfister gave a shout-out to his union crew while on stage. "I think what's going on in Wisconsin is kind of madness right now," he explained later. "I've been a union member for 30 years and what the union has given to me is security for my family; they've given me healthcare in a country that otherwise does not provide healthcare. And I think the unions are a very important part of the middle class of America. So I stand strong behind any of the union members in this country and any other country, because all we're trying to do is get a decent wage and have medical care."

Sound mixers Lora Hirschberg (second left), Gary A. Rizzo (center) and Ed Novick (second right), along with presenters Matthew McConaughey and Scarlett Johansson, pose with their Oscars for Best Sound Mixing.

Hirschberg described what Nolan wanted the rich sound of "inception" to achieve: "One of the things that Chris wanted to do with the soundtrack was to kind of delineate the different layers or levels as you're going down from a dream into another dream into another dream - playing a song, slowing it down or speeding it up. And so we did the same thing with other elements in the soundtrack: A gunshot that turns into thunder, the thunder that turns into an earthquake, or rain that turns into an ocean, as you go down the levels. So that was our piece of that expression."

In accepting the Oscar for Best Visual Effects, visual effects supervisor Paul Franklin (left, with Chris Corbould, Andrew Lockley and Peter Bebb) said, "Well, it feels like that top is still spinning."

For more on "Inception":

Oscar Cold Shoulder: Nolan, Moore
Leonardo DiCaprio Gets in Our Heads
Nolan's "Inception" a Dream of a Movie
The Showbuzz: "Inception"
Photos: "Inception" Premiere
"Inception" Sparks Interest in Dreams
Photos: Leonardo DiCaprio
Photos: Marion Cotillard
Photos: Ellen Page

"Inception" (Official Movie Website)
"Inception" Score - Music Samples of Hans Zimmer's Score
Screenplay of "Inception" Written by Christopher Nolan (Download pdf)