The Bourne Identity keeps you in a state of nervous excitation from the opening shot to the fade-out and has a thread of deadpan humor that vibrates alongside the main action like a third rail quivering next to a hurtling train.

The movie stars a buff and all-business Matt Damon as a multi-lingual mystery man who is fished out of the Mediterranean Sea without knowing who he is. As the search for identity leads him to Switzerland and France, this amnesiac discovers that he is a superbly tuned American killing machine named Jason Bourne and that a lot of people are trying to murder him. He's everyone's worst nightmare - including his own.

The movie is a refreshingly brusque and kicky rendering of one man's attempt to leave behind a fast and savage life. Based on a novel by Robert Ludlum (previously filmed as a 1988 miniseries with Richard Chamberlain), the script by Tony Gilroy and William Blake Herron has predictable core ingredients for an international espionage thriller: an aborted attempt to execute an unstable African strong man and tons of cash and multiple identities for our antihero.

But Bourne, at the start, has forgotten about all that. And once he understands who he was, he wants to say goodbye to all that - while the CIA and the French police scour Paris for any sign of his existence and other virtuoso assassins make plans to knock him off.

What takes the edge off the film's brutality is the black-comic spectacle of a secret agent getting re-acquainted with the mental and physical reflexes that $30 million worth of training have drummed into his muscles, brain and nervous system. Damon shows himself to be enough of an action star to communicate both the threat and the outrageous farce inherent in this idea. When a Swiss cop shakes a baton at Bourne, the actor conveys in a split-second that he realizes his power to play turnaround; then Bourne grabs the baton, to near-lethal effect.

What gives the movie an emotional hook even after his profession becomes clear is the bond Bourne develops with a Eurodrifter named Maria (Franka Potente, of Run Lola Run). This woman has a past as hazy as Bourne's - because of her vagabond temperament, not because of her vocation (if she has one).

For The Bourne Identity to work, we need to believe that Bourne still possesses a human identity worth saving. His relationship with Maria convinces us. Potente is superlative at conveying the covert longing of a gypsy soul for someone who will see the poetry in her speed-demon conversations and the beauty in her raggedy wildness. The way she plays Maria, the woman is independent without being willful about it - a gal the right man of action can trust.

And Damon matches up surprisingly well with her. He's as spare as she is gaudy, but he expresses real tenderness - you can feel her falling for him when he washes her hair.

Damon is at his best when the movie plays the frantic action off of their budding rapport. He imbues Bourne with an underlying calmness that works like a three-way charm. It gets across the character's compassion, self-knowledge and command.

Doug Liman (Swingers, Go) is not a natural action moviemaker. Either to disguise the work of stunt doubles or to jack up the immediate kinetic force, he shoots the hand-to-hand combat too close in and cuts it too frenetically. The claustrophobic design of these scenes undercuts Damon's martial artistry by making you wonder whether it's all him.

Liman does better when he uses his head in the big set pieces. A chase through Paris scores because every feint and lane change counts; the stunt work never obscures the moves and countermoves of the fugitives and the cops. And there's an apt, stark melancholy to a showdown in a snowy rural landscape, which also points up one of the movie's greatest strengths: casting distinctive performers in the tiniest roles, like Clive Owen of Croupier and Gosford Park, here a hit man known as the Professor.

Chris Cooper wears too nonstop a scowl as a CIA boss, but Brian Cox is subtly wily as Cooper's boss, and Julia Stiles brings an element of intrigue to a part that goes nowhere, as a CIA communications liaison. The casting helps save the movie from becoming too neatly worked-out and contained and helps keep us focused on what it's supposed to be all about: a vestige of humanity.

Watch Michael Sragow's movie reviews Thursdays at 5:30 p.m. on ABC2 News, and online at SunSpot.net.

The Bourne Identity

Starring Matt Damon, Franka Potente

Directed by Doug Liman

Released by Universal

Rated PG-13

Running time 118 minutes

SUN SCORE * * *