Xenophobic themes are nothing new in the horror genre, with countless cautionary fright tales telling of unsuspecting travelers abroad who don't return to their homeland in one piece—if at all. Indeed, there exists a fear in many, if even subconscious, of the foreign or unknown, and filmmakers of the macabre know exactly how to exploit this notion in their favor. Dutch writer-director Tom Six milks it to the hilt with "The Human Centipede (First Sequence)," and then goes a step further into the sort of unimaginably bleak, despairing, beyond nightmarish territory that actually makes the thought of death by hacksaw or harpoon sound desirable in comparison. At the forefront—when he's not hauntingly lingering motionless in the background, that is—is a villain so unforgettably chilling and believably maniacal that he alone does enough to smooth out the film's rougher edges and plaguing unanswered questions.

Young, nattering American friends Lindsay (Ashley C. Williams) and Jenny (Ashlynn Yennie) are traveling across Europe when, en route to a nightclub, their rental car gets a flat tire. Stranded on the back roads of Germany, they finally come upon a house in the clearing and seek the help of its owner, retired surgeon Dr. Heiter (Dieter Laser). They want him to call a tow truck, but he has other plans in mind. Coming to after being drugged, Lindsay and Jenny find themselves strapped to hospital beds, they and Asian kidnap victim Katsuro (Akihiro Kitamura) the three test subjects in Dr. Heiter's fiendish plan to construct a human centipede. Connected by their gastric systems and sewn ass to mouth, they now have two choices: submissively become the doctor's plaything, or rustle up all the willpower they've got to somehow escape their hellish ordeal.

If that synopsis sounds simply repulsive, causing your imagination to wander to the most nauseating of images, it should be said that "The Human Centipede (First Sequence)" does show a certain amount of restraint without ever going soft. Hence, Dr. Heiter explains the horrific procedure and consequences to his subjects beforehand (complete with projected illustrations) so that one is spared some—the operative word being some—of the graphic details when he puts his plan into action. Writer-director Tom Six doesn't quite cover all the logistical queries audiences may have, such as the body's need for water to survive (a shot of Dr. Heiter intravenously giving it to middle and back sections Lindsay and Jenny could have quickly cleared this up) and the lack of necessary nutrients found in fecal matter, but he explores enough of them to be able to buy into it in cinema terms without things becoming patently ridiculous.

That the picture comes with a "100% medically accurate" stamp is probably stretching the truth a bit, but no matter. The film achieves exactly what it sets out to do—shock, disturb, disconcert, and force the viewer to ask what he or she would do in such a situation—and then grows to be a little more than just an exercise in revilement. Lindsay and Jenny are portrayed at the start as irritating and ill-equipped to be on their own in the real world, let alone in a place completely alien to them. Trapped along the road when their tire goes kaput, they are accosted by a fellow driver—a local, no doubt, speaking a language they do not understand—who pulls up and sexually harasses them. Thinking the worst is behind them after the perv speeds off, the two gals abandon their lone security—the confines of their car—and wander into a far greater danger than either can imagine. Their whiny personalities—or is it the performances of newcomers Ashley C. Williams and Ashlynn Yennie, far better when their mouths are sewn up and they must act with little more than their eyes, that are annoying?—do not exactly make them very sympathetic at the onset, but director Tom Six's achievement is in devising a destiny for them so awful in every way one wouldn't wish it upon their worst enemy. Thus, by the half-hour mark, the viewer is actively on Lindsay and Jenny's side, even when the former makes a numbskull decision in the midst of an attempted escape that will cause a few smacks to the forehead.

While it is sheer coincidence that the girls cross paths with the psychotic Dr. Heiter—the self-proclaimed "leading surgeon in separating Siamese twins," he has chosen in his retirement to test out the direct opposite, conjoining first Rottweilers and now humans—their Ugly Americanism seals the deal on their fates. Heiter's other victims, whom he actively hunts and shoots with debilitating darts in order to bring them back to his lair—i.e., a truck driver, then what appears to be a young Asian businessman—are interestingly also foreigners to the country, easier to make disappear without too many people asking questions. Bringing things full circle, Katsuro calls Dr. Heiter a Nazi at one point, stereotyping his nationality while at the same time figuratively equating him with a monster. He isn't far off in that particular judgment.

"The Human Centipede (First Sequence)" follows classic narrative conventions while putting a spin on genre expectations. Dr. Heiter isn't above killing if he has to, but that isn't his motive. No, what he purposes to do with his victims is far worse than any run-of-the-mill slasher with a knife. Jump scares, too, are mostly left out of the proceedings, not coming when the viewer most expects them as a means of building up one's thick apprehension. It's fun to be on edge, expecting things that don't come and vice versa. Adding to the picture's dread-drenched nature is a top-notch production design—the house chosen for Dr. Heiter is, at once, a beacon of deceptively peaceful normalcy and a sterile, well-kept, off-center museum of white walls, large windows, abstract art, long hallways, rooms of the unknown, and a secret in the basement—and a close to brilliant performance from Dieter Laser. Laser's slim, tall frame, pale skin, and speckless white doctor's coat are imperative to his character, a lonely, deranged man whose past profession has given him a dangerous case of narcissism—in one scene, he gets lost in a hand mirror and kisses himself—and an outright God Complex.

Following the intentionally and impeccably conceived dismay and abhorrence of the first seventy-five minutes, what could one possibly be expecting for an ending? The finale of "The Human Centipede (First Sequence)"—a sequel, subtitled "Full Sequence," is scheduled within the next year—will not be given away, but it adds freshness to the usual climactic chase scene by leveling the score and forcing both parties to do something other than run, then leads toward a final scene far more psychologically terrifying, staggeringly tragic, and plainly twisted than just about anything the horror arena has ever cooked up. "The Human Centipede (First Sequence)" is an inconsistent motion picture, stronger in certain areas than in others, but when it works, it works like gangbusters on the strong of stomach. The film burrows past one's defenses like a fungus and takes root in the mind, where one can scarcely believe what he or she is watching, yet can't help but be impressed by the audacity of it all.