By JASON W. LLOREN
San Francisco Blast Bureau

"Face/Off," starring John Travolta and Nicolas Cage, takes the tried and true action theme of duality and plays it to full hilt. The bad guy becomes the good guy. The hero dons the villain's mask -- literally.

Under the direction of most filmmakers, the premise would be ridiculous, like some Jean-Claude Van Damme film, but here, in the able hands of Hong Kong action auteur John Woo, it not only works but breathes with intensity.

The set-up sounds ridiculous: FBI agent Sean Archer, initially played by Travolta, is after Cage's terrorist Castor Troy, who fatally shot Archer's son several years ago. There's a big shootout -- explosions, car chases, jet-copter pursuits, the works (And that's just the first 15 minutes) - ending with criminal brother-in-arms Pollux Troy in handcuffs and Cage in a coma (much like his performance in that overblown summer action dud "Hot Air").

The feds then get wind that Troy has previously planted a chemical bomb that's about to blanket L.A. in fatal smog in a few days. The solution: Black-ops surgery is used to plant Cage's puss on Travolta so Archer can go undercover and learn the whereabouts of the bomb from the incarcerated Pollux.

I know, I know. Sounds stupid. The original script had a futuristic setting so the ultimate facelift subplot seems almost plausible. But hand it to Woo -- not only does the gimmick work, but he crafts a well-wound psycho-drama pumped up with his usual flare for beautiful violence.

Plot twist #1: While Archer, now played by Cage, is playing undercover in prison, a faceless Troy emerges from his coma. Troy then forces the plastic surgeon to slap Archer's face, conveniently left behind in the operating room, on his head. Now Archer's stuck in prison while a delightfully evil Troy, now played by Travolta, is flirting with Archer's daughter, boning his wife and becoming the cause celebre among the L.A. FBI. (Take our word, it's not as confusing to follow as it reads).

Travolta/Troy springs Pollux out of prison and Cage/Archer eventually escapes. Now the cat and mouse are let out of the bag and the action high runs high.

Initial doubts that Cage and Travolta can mimic each other are erased immediately because Woo allows the characters to flourish in both actors. Travolta assumes Troy's walk, his vocal cadence. Cage becomes Archer by assuming his pain. My friends complained about the dead time in between the action but it ultimately served a purpose. Instead of simply letting the hero and villain loose on the street, Woo fleshes them out emotionally and mentally. Much credit for this goes to actress Joan Allen, who, as Archer's wife, squares off with both Travolta and Cage.

Throw in a hundred guns and a thousand rounds, add a speedboat or two, and combine with some in-church gunplay and plenty of inventive stunt work and you have an explosive action film.

Woo has employed similar themes in his films "The Killer" and "Hard-Boiled." "Face/Off" is almost the ultimate realization of hard-core action and psychological duality. It's well-paced, well-scored, and let's face it, there's some hella cool guns. The only thing that seems to be missing is Chow Yun-Fat.

Race/Off to a theater and see "Face/Off."