Each year, one movie emanating from Sundance pushes the boundaries of human decency. It incites walkouts by the dozen. Debates rage on in cafes and buses. At the 2007 fest, this honor went to Zoo, a documentary about a man who died of peritonitis after receiving consensual anal sex from a horse. Two years ago, it was the psychological thriller Compliance, about a man posing as a cop who phones up a fast food joint and manipulates a pretty teen checkout clerk into being degraded and assaulted by her peers.

Wetlands (Feuchtgebiete) is the runaway favorite for 2014’s most notorious Sundance flick.

Directed by David Wnendt, and adapted from the bestselling German erotic novel of the same name by Charlotte Roche, the film opens with a teenage schoolgirl skateboarding down the street. “As long as I remember, I’ve had hemorrhoids,” she says in voiceover, in a cheeky nod to Goodfellas. She walks barefoot through a disgusting public restroom filled with brown water up to the ankles, enters a stall, applies a glob of zinc cream on her finger, and shoves it up her rear end.

Meet Helen.

The strange teen, played by Carla Juri, who’s a dead ringer for Greta Gerwig, has some major hygiene issues thanks to her germaphobe mother (Meret Becker), who advises her at the age of 8 that “a pussy gets sick way easier than a penis does,” so hygiene is of paramount importance. She’s also sadistic. In an episode straight out of a Roger Ailes biography, Helen’s mother convinces a very young Helen to jump off a rock wall outside their home and into her arms. She extends them outward. Helen jumps, and her mother backs away, letting her fall to the ground. “Don’t trust anybody, not even your parents,” she warns. “Better a scraped knee now than a broken heart later.” (Her divorced father, an emotionally distant lothario, isn’t much better.)

So Helen, naturally, rebels against her germ-averse, very Catholic mother and transforms herself into, as she says, “a living pussy-hygiene experiment.” She enjoys sitting on filthy public toilet seats and wiping her vagina around the rim in a circular motion, inserting vegetables—carrots, zucchinis, potatoes—into her vagina, and having her lady parts emit a “lightly bewitching odor” to attract the opposite sex. Then, when she has her prey in her clutches, she takes close-up shots of men’s orgasm faces with her cellphone while tugging them off, and then proceeds to walk all the way home with their semen on her hands. She becomes obsessed with bodily fluids, often inserting her fingers into various orifices before licking them clean.

But Helen isn’t the only oddball in town, and she soon finds a kindred spirit in Corinna, an equally adventurous young gal. Corinna becomes a pariah of sorts after word gets out that her first boyfriend, a heavy metal drummer, enjoys it when she takes dumps on his belly. Later in the film, the two girls swap bloody tampons, then wipe menstrual blood on each other’s face, proclaiming themselves “blood sisters.” At one point, one of Helen’s tampons gets stuck inside Corinna, so she removes it with a grill utensil, before handing the bloody tool back to her father, who subsequently uses them to flip steaks.

Helen fantasizes about reuniting her divorced parents, telling her mother she wishes to tie them in bed together ‘til death do they part.

One day, while shaving, she has an unfortunate accident, resulting in an anal fissure. She’s condemned to the proctological ward of a hospital. She wishes to have her parents meet her at the hospital at the same time, hoping that will reunite them. Confined to her hospital bed by the sinister Dr. Notz, Helen becomes lost in her own mind, fantasizing about various sexual and drug-fueled experiences that may or may not have happened (she isn’t the most reliable narrator). She imagines a plant sprouting out from her vagina, and has numerous dreams about Robin (Christoph Letkowski), her hot male nurse that she has a crush on. In one scene, while the two are eating pizza, she tells Robin a story of five men masturbating—and then ejaculating—onto a spinach pizza, which is then served to a house of unsuspecting girls whose father just happens to be a food chemist. We see the sperm flying in slow motion and splashing onto the pie as Strauss’s The Blue Danube plays.

“I would love to eat a pizza like that,” she says, testing Robin. “It would be like five men jizzing right into my mouth.”

Helen’s infantilization at the hands of the Dr. Szell-like Notz, along with her hospital imprisonment and subsequent fantasies, recalls Charlotte Perkins Gilman’s celebrated short story, The Yellow Wallpaper. It’s a bizarre fable that seeks to shatter a number of female-related taboos, believing that women’s natural scents and fluids should be celebrated, not abhorred. Wetlands is beautifully lensed, and includes a number of eye-catching sequences, including a drug-fueled rampage throughout the city, as well as some nifty editing. Despite the various bodily secretions on display, the film looks spectacular.

Once Helen’s surgery is a success, she’s cleared to leave the hospital. But her parents haven’t reunited yet, so she conspires to stay in the hospital by ramming the pedal of her hospital bed up her rectum, which leads to emergency surgery. We learn later on that Helen is very mentally ill, stemming from a dramatic incident in her childhood (which is alluded to throughout the film via flashbacks).

Wetlands will be singled out by cinemagoers for its X-rated content, but it’s also, in a way, a wacky satire that sends up people’s—in particular men’s—fear of female sexuality, femininity, and cleanliness (its title, after all, is a reference to women’s genitals). Others will see it as pornographic. Roche’s tome split audiences along the same lines, but shot to No. 1 on the Amazon charts upon its 2008 release, selling half a million copies that March, according to The Economist, before going on to sell close to two million copies worldwide. Whether the film version will catch on in a similar fashion remains to be seen, but it will certainly raise some eyebrows.