Fans of the "pitiless/merciless killers" school of horror should get a jolt out of "The Strangers," a harrowing real-time tale of an assault on a remote country home.

This is "Funny Games" without the smug, rich villains and smug, taunt-the-audience director. It's "When a Stranger Calls" with the menace coming from a knock on the door in the middle of the night, not a phone call, or "Vacancy" set in a ranch house, not a hotel.

Yeah, it's derivative as all get out. You've seen one Hitchcock knockoff, you've seen them all.

But "The Strangers" is subtle, by the standards of such thrillers. It builds suspense in its own sweet time. Writer-director Bryan Bertino manipulates, lets us see things that the would-be victims don't, scary things. He shamelessly yanks our chains, allowing the viewer to anticipate the terror to come.

And he cast this well. Liv Tyler's reactions to the hooded, masked strangers who torment her and beau James (Scott Speedman) are human, sane and perfectly rational. A hooded hulk stands outside her window just as she opens a curtain, and she does what we'd do. She screams bloody murder. Her character's reality keeps the film's little lapses in logic from utterly tripping up its brisk 80 minutes.

Kristen and James have just returned from a party. They're gloomy, drained, returning to a house with rose petals littering the floor, the bath and the bed, champagne on ice. Something hasn't worked out.

And then come the knocks on the door, the scratches on the wall, the chimney suddenly clogged.

As the ancient turntable skips over morose folk and Merle Haggard records, the script sends James out the door at 4 in the morning, leaving Kristen to face the unknown on her own. It makes James question what may or may not be happening to Kristen.

And it hurls guns and knives and axes and the obligatory dead phone at the victims, and dares them to find a way to survive until daylight.

"Why are they doing this to us?" Kristen says, asking the obvious.

"It's just us and them," James mutters, stating the just as obvious.

The latest trend in horror, a reaction to the excruciatingly graphic torture-porn genre ("Saw"), keeps some of the worst violence away from the viewer. It's aimed, industry watchers tell us, at teenage girls, who love to shriek at things that go knock/clatter/scratch in the night. "The Strangers," despite its R rating, falls neatly in with "Prom Night," "When a Stranger Calls" and their ilk.

It's more scary than silly, more rational than ridiculous. And if it's shrieks you want from teen girls in the audience, "The Strangers" gets the job done.