"War of the Worlds" is finally about to descend upon us. Or at least a chosen few here at this advance screening. Publicity for the movie has been everywhere -- well, actually, publicity for its star, Tom Cruise, and his love life, his religious practices, his interactions on the couch circuit. But the film itself? Tightly under wraps.

So cell phones, bags, even small clutches are confiscated. There is a metal detector at the theater door. Inside, audience members are ominously warned that there will be surveillance sweeps throughout the film, and should anyone be caught with electronic contraband, the screening will be halted altogether.

Finally, the screen flickers, the credits begin to roll, and then comes a whispered question:

"Tim Robbins is in this?"

He is. No, Robbins is not your usual blockbuster sci-fi, action-hero kind of guy. Even he admits that. ("I was in 'Top Gun,' though," he says, naming another big Cruise vehicle.) But "War of the Worlds" isn't your usual blockbuster sci-fi, action-hero kind of movie. Based on the 1898 H.G. Wells novel, it's about the end of the world, sure, but it's also a profound exploration of the human fear and terror that come from confronting the unfathomable and what that does to body and mind. The new movie version -- as reconfigured by director Steven Spielberg for the 21st century -- is heavily influenced by how Americans perceive fear and terror in post-9/11 America.

"It's certainly about Americans fleeing for their lives, being attacked for no reason, having no idea why they are being attacked and who is attacking them," Spielberg says during the New York stop of the press tour.

So if Cruise (and special effects) are the movie's twin superstars, then Robbins -- whose role consists of a 20-minute sequence during which he shares a basement with Cruise and his movie daughter, played by Dakota Fanning -- is the embodiment of that terror. Cruise wants to race his family to freedom. Robbins, as Ogilvy, is a tortured soul who, when confronted by terror and loss and confusion, goes insane. Spielberg called him directly about playing the part; Robbins accepted immediately after reading the script.

"I thought, what a great challenge to have to create a distillation of terror within one basement and one person after this onslaught of terror," Robbins says. "After the special effects, and after the massive scope of what you've seen, the humanity that has been lost, the madness that has ensued, then to take all of that and make it a little microcosm."

He shakes his head. His antiwar positions are well known and these are subjects that fascinate him, preoccupy him and, at times, even terrify him. The nature of war. The impetus that drives one world -- or, as he puts it, one country -- to attack another. The way terror changes human nature, perverts it.

Robbins saw the completed film only recently -- "I think [Spielberg] was working on it right up until last week," he says -- and the scene he finds most terrifying is revealing. He is not in it. Neither are the aliens. It's not a moment of massive destruction or massive death. It is, instead, a scene in which Cruise and his children find themselves the target of an out-of-control mob.

"It's terrifying, because it's exactly what happens," he says. "You lose your sense of compassion and reason, and you just try to survive. And you think about war zones, and you think about how that must happen. The inhumanity that occurs within a war zone."

The day before the New York premiere of the film, Robbins, 46, is in the Manhattan loft that is home to his production company, Havoc Inc. On his office wall are framed caricatures of the neoconservatives whose "lies about the war" he calls "sinister." Leaning against the wall in his "game room" (pool table, NBA arcade game, etc.) is a large poster for "Embedded," the antiwar play he wrote and directed in New York, a filmed version of which has just come out on DVD through Netflix. The play/film is a satire that pillories several members of the current administration (there are grotesque caricatures of Dick Cheney, Paul Wolfowitz, Condi Rice and Richard Perle, among others) and the mainstream media for its coverage of the war in Iraq. The reviews weren't good, but the shows -- the play ran in New York, Los Angeles and London -- sold out for months.

"The audience was really electric, and the laughter was kind of like a bark -- a fear-based laugh, or anger-based laugh," he says, talking about the New York premiere. "Sometimes laughter is not necessarily being happy, it's a release of a fear and that's what I heard that night. People told me it was something they needed to see."

Unlike fellow antiwar activist Sean Penn (who was his co-star in the 2003 film "Mystic River," for which they both won Oscars), Robbins has not felt compelled to hop a plane to the Middle East. It has to do with the fear thing. His own, that is. He has a recurring nightmare -- "it has to do with violence, and it has to do with being the wrong person, the unintended person."

He had one of those real-life moments two years ago, when he was on the subway with his son, Jack Henry, then 14. Out of nowhere, he sensed, intensely, that something was about to happen. Something unreasonable. Then, he said, eight or nine teenage boys went on a "wilding" -- attacking the conductor and injuring an 11-year-old boy.

"I remember turning to my son," Robbins says, "and saying, 'Did you feel that? Before that happened, did you feel that?' And he said, 'Yeah, I did.' And I said, 'Remember that. That's the survival instinct taking over. If you can feel the energy before it happens, you can avoid it.'

"What terrifies me most," he adds, "is to be in an area where there's no reason. And I've seen glimpses of it in my life, growing up in New York, where things got crazy in a mob. It's something I know in my gut, instinctually, to avoid now. So why go to an area where you know it's going to happen?"

So now we're back to war zones. Given an opportunity to talk about "Embedded" -- or Iraq, or the Bush administration, or any of the many politically charged issues that he's passionate about -- Robbins is happy to take it. He spends a full 10 minutes trying to explicate a recent BBC documentary he just finished watching, "The Power of Nightmares," which also explores the war and the reasons the United States entered into it. He does not get angry, or over-excited, or come across like a zealot and, unlike much of Hollywood, he has no fear of the backlash that might come his way for expressing himself publicly. Both he and his longtime partner, Susan Sarandon, are well acquainted with the adverse reaction that speaking out can bring -- they first ran into public condemnation when they denounced the first Gulf War more than a decade ago.

"What I want to do is put the information out there and let people decide for themselves," he says.

Only right now he is, technically, supposed to be promoting "War of the Worlds." So he's gone on the "Today" show and baked cookies. He's done Letterman. He's answered questions about what E.T. would think about the aliens in his current film ("E.T. would be [ticked]") and whether he believes there is life beyond Earth (he does). Jerry Springer will be calling shortly, which is why he's trying to make his way through an egg sandwich while conducting an interview -- he apologies profusely for this, but this is his life for now.

"It's crazy," he says. This is not his usual genre, the big summer movie with the mega-budget and the megawatt publicity. He's used to acting in, or directing, films that mostly require some begging before someone produces the cash to back them. Even "Mystic River," for all its critical success, had trouble getting made at first.

So can he understand (and forgive) why someone who has yet to see his character in the film might find it surprising that he's attached to this particular picture?

"You mean I'm never going to be your action hero?" he teases.

Not that he ever wanted to be. And he wants it even less after having a ringside seat for this particular Hollywood circus. Oh, it's not that he didn't love working with Spielberg. It's that whole Cruise thing. The TomKat phenomenon. The ever-present paparazzi. The total obsession over what Cruise might do or say next.

"It's surreal, is what it is," he says. "It's the same thing with Brad Pitt. Ultimately, I feel like you just have to give it a rest. Let these people live their lives. It's okay to be in love. It's okay to be goofy if you're in love.

"I don't know how I would react in situations like that," he says. "And I don't want to."

Tim Robbins in his Manhattan office, above, and with Tom Cruise and Dakota Fanning in "War of the Worlds," in which he plays a man driven insane by terror and loss.

Tim Robbins in his office at Havoc Inc., his production company in Manhattan: "What terrifies me most is to be in an area where there's no reason."