In the intermittently compelling but unavoidably improbable "The Jacket," Adrien Brody's sweet-natured Jack Starks is one unlucky guy. A Marine sergeant in the Persian Gulf War in 1991, Starks smiles kindly at a native kid, who responds by shooting him in the head, nearly killing him and leaving him in a state of amnesia.

After a long recovery, Starks is seen a year later hitchhiking in his native Vermont, where he encounters a young woman, Jean (Kelly Lynch), with a small daughter, Jackie (Laura Marano), by the roadside. Jean is intoxicated to the point of sickness, and her dingy pickup has stalled. Starks quickly gets the truck going, but the incoherent Jean responds as if he had tried to molest her daughter. Starks continues on his way, hitches a ride with a young guy (Brad Renfro) who is promptly stopped by a highway patrolman. The driver immediately opens fire on the officer, flees the scene — and Starks, who was wounded in the crossfire and blacked out, is blamed for the cop's murder and promptly sentenced to an institution for the criminally insane.

Starks' horrendous misfortunes only escalate, for he has fallen into the hands of Kris Kristofferson's implacable Dr. Becker, who regards the inmates as criminals first and patients second and submits Jack to a hideously unorthodox behavioral modification treatment that involves straitjacketing the victim, injecting him with a huge dose of an antipsychotic drug — never mind that Jack isn't psychotic in the first place — and shoving him into a morgue-like drawer for hours on end. According to Becker it's all in the name of rehabilitation.

All the above composes the film's elaborate setup. Once imprisoned inside the coffin-like space, Jack not only flashes on fragmented images of what happened to him in the Persian Gulf and to what really took place at that fatal roadside shooting but also flashes forward to 2007. In a series of time-trips, Jack encounters the now-adult Jackie (Keira Knightley), a beautiful but deeply troubled roadside-diner waitress, and after a shaky start they're playing detective to find out what happened to Jack on the fateful day of Jan. 1, 1992.

It seems safe to say that whether this film works for the viewer depends upon his or her ability to suspend disbelief sufficiently to buy into the time-travel angle, which many will be unable to swallow. However, even the viewer who finds the premise too far-fetched to accept may nonetheless come away impressed with the ambitiousness of the attempt and even be moved by the emotional effect of the film's well-staged concluding sequence, which plugs into a universal yearning to step back into the past and alter the future, if even partially, for the happiness of another.

"The Jacket" was written by Massy Tadjedin from a story by Tom Bleecker and Marc Rocco, and directed by John Maybury, best known for "Love Is the Devil," a captivatingly corrosive take on Francis Bacon, who could be as ferocious as his paintings. "The Jacket" is ambitious and stylish, striking a tone of cool contemporary detachment enhanced by Brian Eno's silky score. If the film finally seems silly and sentimental, it is no less a heartfelt quality effort.

It's hard to imagine anyone but Brody in the role of Jack Starks, and it's not an unreasonable change of pace for the actor. His elegant thinness, his sensitivity and courage, his beatific smile are ideal for Jack's saintly martyrdom; Brody could be a model for a medieval likeness of Jesus nailed to the cross. The film sets up Jennifer Jason Leigh's idealistic and dedicated Dr. Lorenson as a contrast to the retrograde Becker only to reveal her as a timid and hopelessly compromised careerist. Also contributing a strong presence are Daniel Craig as Jack's earthy but deluded fellow inmate, and Brendan Coyle and Mackenzie Phillips as a pair of brutal aides at the institution. For those able to go along with it, "The Jacket" could emerge as a provocative fable of injustice and redemption.

'The Jacket'

MPAA rating: R for violence, language and brief sexuality/nudity

Times guidelines: Considerable prolonged brutality, brief sensuality, adult themes

Adrien Brody...Jack Starks

Keira Knightley...Jackie

Kris Kristofferson...Dr. Becker

Jennifer Jason Leigh...Dr. Lorenson

Brad Renfro...Stranger in station wagon

Kelly Lynch...Jean

Laura Marano...Young Jackie

A Warner Independent Pictures and Mandalay Pictures presentation in association with 2929 Entertainment of a VIP Medienfonds 2/VIP Medienfonds 3/MP Pictures co-production in association with Rising Star. A Section Eight production. Director John Maybury. Producers Peter Guber, George Clooney, Steven Soderbergh. Screenplay by Massy Tadjedin; from a story by Tom Bleecker and Marc Rocco. Cinematographer Peter Deming. Editor Emma Hickox. Music Brian Eno. Costumes Doug Hall. Production designer Alan MacDonald. Art directors Caireen Todd, Stephen Campbell. Set decorator Liz Griffiths. Running time: 1 hour, 43 minutes. In general release.