Writer-director Tom Six conceived of 2010's "The Human Centipede (First Sequence)" with an idea so unimaginably original and grotesque—and, as the savvy marketing touted with perhaps a tinge of exaggeration, "100% Medically Accurate!"—that it was destined to earn itself a certain amount of infamous notoriety. Visually sleek, sterile and fascinatingly suggestive, the film, like 1974's "The Texas Chain Saw Massacre" before it, prompted countless critics and viewers to incorrectly claim it was far more graphically violent than it actually was. In truth, Six suggested more than he showed, and the experience was no less skin-crawling because of this. For "The Human Centipede 2 (Full Sequence)," the second in a pre-planned trilogy, the filmmaker more or less taunts those who labeled the first movie as disgusting by presenting the world with a sequel that truly is an explicit gross-out. Make no mistake, this little cinematic burst of savagery and bathroom pornography is as balls-out as its predecessor was comparatively restrained. Somehow, though, for better or worse, the content rarely seems gratuitous so much as daringly honest in its depiction of a demented maniac who gets more than he bargained for when he turns to serial torture and murder. With stark black-and-white photography and a meta-loving premise that exhibits newfound inspiration, "The Human Centipede 2 (Full Sequence)" isn't just a rehash of what's come before. It's also, to its detriment, a whole lot more mean and pessimistic.

Martin (Laurence R. Harvey) is quiet, stocky, bespectacled, possibly slow, and utterly obsessed with "The Human Centipede (First Sequence)." Working as an overnight parking garage attendant, he watches the DVD on a loop and pours over his self-made scrapbook about the film, fantasizing about what it would be like to recreate a human centipede—that is, attaching people mouth to anus to simulate a single digestive tract. Not satisfied with just three people, he ups the ante by brutally attacking and kidnapping twelve, storing them away at an empty warehouse he's taken over. Having beaten to death his wretched mother (Vivien Bridson), Martin has done away with the only constant presence in his life and can now solely commit to his ghastly project. What he doesn't count on is how difficult the process will be to put together; in the film, it was carried out by a talented, albeit psychotic, surgeon, and Martin is definitely no doctor.

"The Human Centipede 2 (Full Sequence)" moves away from the themes of xenophobia and narcissism found in the previous picture to explore the subjectivity of art, the psychological ramifications that cinema can have on an already-sick mind, and the fine line between artifice and reality. Some of it is a bunch of hooey and some of it is clearly to be treated in jest, yet there is also a bit of truth and cleverness to its self-referential blurring of fact and fiction. It's completely unbelievable that Martin, who is not seen uttering a word throughout, would be able to pose as a casting agent for Quentin Tarantino in order to lure the actors of "The Human Centipede (First Sequence)" into his clutches, but there is something oddly innovative and rather creepy about such a notion, anyway. Enter returning actress Ashlynn Yennie, playing a hopefully broad version of herself, who finds her life suddenly and horrifically imitating the film she starred in. On the positive, she's heading up the front of the centipede this time rather than stuck in the back. On the negative, Martin is a remorseless amateur who has no idea what he's doing, committing so many violent atrocities upon his twelve victims even before they've been staple-gunned to each other's backsides that it's difficult to keep track of them all. He thought it looked so easy in the movies. With the pieces of his centipede before him, he quickly gets a taste of the dirty, sickening, beyond-unthinkable mess he's gotten himself into. Things definitely do not work out as he expects them to.

If the first hour is gritty and perverse as Martin's preparations take hold and his home life dissolves—moments before killing his mom, he catches her stabbing what she thinks is his covered body in bed—the final act is the real test for what the viewers' stomachs will be able to take. From slicing tendons to hammering out teeth to giving each centipede unit a shot of laxatives, it's all captured fearlessly and heinously, up close and personal and with scatological sound effects to provide an exclamation point to the set-piece. Because Laurence R. Harvey is so ickily committed as Martin—it is certainly a memorable debut performance, if nothing else—and because Tom Six is so capable of both involving audiences on a primal level while providing subtext for them to mull over, the film narrowly avoids feeling like empty-headed excess.

What writer-director Tom Six could afford to show next time is a little more empathy toward his characters, each one introduced as despicable and unpleasant moments before they are hit over the head and tied up. It's a bleak portrait of humanity, for sure, and one that demands a little diversity in the future if Six hopes to one day branch out beyond pure shock value. Meanwhile, dialogue is blessedly minimal—"He's gonna stitch us up ass to mouth!" one of Martin's victims stiltedly exclaims, apparently familiar with the franchise he's about to become a part of—and reasoning behind the villain's madness is vaguely sketched outside of the suggestion that his father abused and molested him as a child. In final evaluation, "The Human Centipede 2 (Full Sequence)" is as rough around the edges as it is a rough-and-tumble experience, but there is also no point in denying that the film is effective and skillfully made, going places few legitimately-distributed movies dare to go while enveloping its audience in appropriate dread and despair. Like it or hate it, you can't say you weren't warned.