"V for Vendetta," which had an advanced screening at South by Southwest Wednesday, is thrilling as cinema but questionable as politics. Well-crafted and often stirring, it's an overtly political action film that makes a few trenchant points, but it's tough to come away from the film with a coherent message. But it's worth seeing nonetheless.

It's the year 2020, and Britain has become a fascist state. The government has rounded up the undesirables, used the media as a fear-mongering tool, and enforced a strict curfew on its cynical but weary populous. In the bowels of the city, V (Hugo Weaving), a man once imprisoned and tortured for his dissent, is plotting a violent overthrow of the government, as well as revenge against his individual tormenters. He stumbles upon Evey (Natalie Portman), who is first skeptical but eventually becomes his partner in revolution. The action scenes are well-staged, and the movie has a few dark laughs (including a subversive play on Benny Hill). The supporting players, which include John Hurt, Stephen Rea and Stephen Fry, are excellent.

V is a man with a lot on his mind, and while he commits some pretty gruesome acts of revenge, he's a romantic at heart; he likes Shakespeare, "The Count of Monte Cristo," and Cat Power, and has Jan Van Eyck's "Arnolfini Wedding Portait" on the wall, all of which are banned under the regime (though it's never adequately explained how he acquired his martial arts skills and amassed such staggering wealth). The sequence in which Evey makes the transformation from skeptic to fearless freedom fighter (drawing heavily from Dreyer's "The Passion of Joan of Arc") is one of the more moving in the film, and never more so than when she reads a letter in her jail cell written by one of the regime's innocent victims.

But in the wake of 9/11 and the London terrorist attacks, it's not unreasonable to feel more than a little queasy rooting for this guerilla campaign. The film is on firmer ground in other respects, as when it makes the claim that governments should be beholden to their people (no argument there) or that civic engagement is a necessity, especially in particularly troubled times (ditto). In all, "V for Vendetta" is a provocative film, not least because it's sometimes unclear what reactions it should be provoking.