Despite the similarity of the title, "Them" (called "Ils" in its native France) is not a remake of 1954's ant-invasion movie, "Them!" Planted more firmly in reality, the film—a lean and suspense-filled horror tale inspired by true events—imagines the kind of terror that must be felt when a person's private home is invaded. Taking place almost completely in the span of a single night, writer-directors David Moreau and Xavier Palud cut right to the point, working up a sense of unease that is all the more effective because there are no subplots or extraneous supporting characters to get in the way of the centerpiece storyline. Where "Them" does run into problems is in an unsatisfying payoff that lessens a mystery that should have remained just that.

Clementine (Olivia Bonamy) and Lucas (Michael Cohen) are a content couple living in an old, spacious and, most importantly, secluded house in the woods. Hours after Clementine receives a cryptic phone call that she chalks up to being a prank caller, the two of them are awakened by strange noises. They think they're coming from someone outside on their property, but have no idea just how close the intruders really are.

"Them" is simple and direct about its intentions, and at 74 minutes, is practically one really long sequence stretched out over an hour. The prologue is the only deviation from the focus on Clementine and Lucas—a fantastically scary opener in which a bickering mother (Camelia Maxim) and teenage daughter (Maria Roman) become stranded on a lonesome stretch of country road and are subsequently stalked by an unseen person or presence. The use of rain, tight camera angles, creepy sound effects, and a feeling of hopeless isolation built within the mise en scene all work together to create a fever-pitch of tension. Directors David Moreau and Xavier Palud know how to work their audience in moments like this, or in later standout scenes where a television keeps turning on every time Lucas leaves the room, or when Clementine is embroiled in a cat-and-mouse game amid a maze of hanging plastic sheets in the attic.

The early and midsection dread somewhat dissipates in a climax where the identity of the villain (or villains) is revealed. One of the most effective aspects of "Them" is the decision to keep the intruders in shadows and background shots. For a while, one isn't even positive that the culprit is human, and it is this lingering lack of knowledge that gives the picture its kick. It should have remained this way from beginning to end, because where the narrative finally leads is a bit disappointing and standard-issue. It should be mentioned, however, that one of the final shots—you'll know it when you see it—does, indeed, leave a truly vivid and haunting impression.

Another recent French horror film, 2005's "High Tension," was a masterpiece that not only cut to the jugular, but led to an ingenious ending that retained a certain abstruseness even as it unveiled itself to be about far more than initially met the eye. By comparison, "Them" is less thematically ambitious, a well-crafted jack-in-the-box toy that is more frightening in its ratcheted apprehension of what is to come than in the ultimate outcome.