By Nicole Sperling
April 16, 2010 at 04:00 AM EDT

STARRING Leonardo DiCaprio, Ken Watanabe, Ellen Page, Joseph Gordon-Levitt
DIRECTED BY Christopher Nolan
WRITTEN BY Christopher Nolan

Christopher Nolan’s new movie is about dreams, and if you think he’ll reveal much more than that — well, you’re dreaming. The director of The Dark Knight and Memento has protected Inception from inquiring minds since day one. The actors had to read the script in his office, or have it hand-delivered to their homes, where someone stood guard outside while they perused it. Even the tense, riveting trailer really only tells you that one of Hollywood’s few truly electrifying directors is up to something. But come to think of it, that’s a hell of a good offer. ”After I read the script, I was sweating, I was so exhilarated,” says Ellen Page. ”There were moments when I was pinching myself that I was involved with this Chris Nolan film. The stuff he does is going to blow people’s minds. It definitely blew mine.” Page won’t elaborate beyond saying that the movie had her doing ”the craziest s— I’ve ever done.”

Inception concerns a group of freelance dream thieves who steal people’s ideas for corporate gain by inserting themselves into strangers’ subconscious while they are sleeping. Leonardo DiCaprio plays Dom Cobb, the group’s leader, who agrees to take on one last job — an extremely dangerous one that could reunite him with the family from whom he’s long been separated. Page plays Ariadne, a college student who joins Cobb’s team. The PG-13 film toggles between dream states and reality, globe-jumping from Morocco, Tokyo, London, and beyond in what DiCaprio calls ”a collage” in which various landscapes ”all blend together and intersect.”

Nolan has been obsessed with dreams since he was a child. Initially, he envisioned a low-budget film more akin to his early work such as Memento than to his übersuccessful dystopian Batman franchise. ”I had tried to write this movie for years as a small film, but it’s not possible,” he says. ”As soon as you deal with the potential of the human mind, how can that be small? Yes, it’s intimate. Yes, it’s emotional. But what I suddenly realized is I had this concept that lent itself to an epic-scale movie.”

Warner Bros. agreed and handed the director a budget in the neighborhood of $160 million. Nolan insists that Inception doesn’t try to confound its audience: ”It’s not a rug-pulling, twisty, turny sort of film. It’s not a film that confuses people.” DiCaprio says even the dream sequences have their own logic and are far from the fantastical imagery of, say, Alice in Wonderland. ”There are no giant flowers or pink clouds in Chris Nolan’s dreamworld,” says DiCaprio. ”Chris was very adamant that the dreamworld should feel real, and even if these are different layers of one’s consciousness, it all relates back to that person. So we took a hard look at every scene in this movie and made sure it had validity and weight to it, no matter what was going on.”

And a lot was going on. Nolan didn’t want to rely on special effects to tell his story, so he constructed massive sets around the world. In London, he built one that rotated 360 degrees and, according to the director, ”altered the performers’ relationship with gravity.” In Calgary, Alberta, he constructed one on top of a mountain and then waited for a huge snowstorm, which in the end was bigger than anything the Canadian province had seen in 30 years.

If you’re eager to know more, you’ll have to buy a ticket. ”We just want to keep something fresh,” says Nolan. ”It’s very difficult making a large-scale film under the glare of attention. Anything we can do to shield the process from outside scrutiny is valuable. When it’s finished, it’s there for people to rip to pieces and judge.” We’re expecting a much happier ending.