It's a credit, albeit a minor one, to Alexandre Aja's horror thriller ''High Tension" that its heroine doesn't wake up screaming in the last shot, because for over an hour the picture feels like a grisly nightmare.
''High Tension" is from France, and it has a distinctly European sense of dread. It doesn't bother with the who or the why, just the what and the how ghastly. Come the film's dumb and insulting last-minute revelation, there's every reason to think it should have bothered trying to explain something. Alas, no. The film ends, inexplicably, with a shrug.
Aja and co-writer Gregory Levasseur cough up a story in which Marie and Alex (Cécile De France and Maïwenn), two law students, drive to Alex's parents' country house. Marie is a tough-looking girl with a punky blond haircut, and she obviously has a crush on the ostensibly straight Alex.
During the car ride, she chastises her friend for ditching her recently to talk to a boy. And, later that evening, she demurs when Alex presses her about her own love life. That night, after Marie has a gotten an eyeful of Alex in the shower, there's a knock on the door, which Alex's father is foolish enough to answer. The poor guy is promptly stabbed and decapitated. Alex's mother is garroted as Marie watches, ''Blue Velvet"-style, though the slats of the bedroom closet. Alex's little brother, the kid in the unfortunate cowboy costume, is shot in the cornfield.
Alex herself is tied up, thrown in a van, and left in one piece, presumably for a pending sexual adventure, and because there's still 70 minutes of movie to go.
The culprit is an old beast in overalls and a cap, with a fondness for running his straight razor ominously along bloody skin. Effectively, he is the bogeyman in ''High Tension."
Anyone familiar with Gaspar Noé's ''I Stand Alone" might recognize the fellow's ruddy complexion, devilish grunt, and cauldron-sized belly -- they belong to Philippe Nahon. In Noé's psychological terror flick, another exercise in awfulness, he played a meat-monger with a ghastly interest in young ladies. Here, he's a different (but not that different) sort of butcher.
''High Tension" is being released by Lion's Gate, which also put out last year's stomach-turning ''Saw." The studio has become quite the grind house -- a home for filmmakers who want not only to sicken, but also to provoke.
Hence the juxtaposition of the killer's arrival with a scene of Marie masturbating. Later, when he binds, gags, and absconds with Alex in his rusty van, Marie steels for her own brand of sadism. Indeed, she winds up trailing them in a GTO whose bumblebee paint job perfectly matches Uma Thurman's ''Kill Bill" racer's suit, right down to the black stripe.
From here the movie seems poised to evolve into a cathartic revenge plot. You don't care about the characters, per se. You just want justice, and once Marie gets her hand on a piece of wood wrapped in barbed wire, the movie is talking to the sick freak in some of us.
But ''High Tension" is a fraud. It doesn't make an iota of sense. (Neither does the decision to dub a third of the movie, and subtitle the rest.) By the end, Aja and Levasseur are making an equation between sexual attraction and homicidal mania that turns standard horror movie craziness upside down.
What happens in the final minutes is narratively dumb -- and psychosexually ridiculous.
That's a shame. Aja knows his way around a suspenseful sequence, which a lot of the directors toiling in this genre don't. But the horrible anticipation he builds is derailed by a gimmick that makes the twist in, say, ''Fight Club" seem perfectly logical. To say more would be to ruin the movie, and why should I do that when its own makers have done it for you?
Wesley Morris can be reached at wmorris@globe.com.