The film "Tore tanzt" (Tore Dances) couldn't open more idyllically, with plenty of sunshine and trees. That is, if it weren't for the harsh, throbbing soundtrack as a slouching blond teenager is baptized in a lake.

Tore is a Jesus freak. He listens to punk music, wears tattered leather jackets and lives in a Christian commune with other religious outsiders. In their universe, God is "cool" and it's normal to wear both a Mohawk and a cross.

When Tore starts to realize that everyone else in the commune doesn't live out their faith as resolutely as he does, he leaves. Then, he befriends the shady Benno and moves in with his family.

But what begins as a spontaneous friendship slowly turns into torture. Benno starts mistreating Tore. First he rations his food; then he beats him. Finally, Tore is forced to prostitute himself to support the family.

For Tore, the horrific experiences are trials sent from God to humiliate him and test his charitable intentions. It's Tore's endless willingness to sacrifice that makes the film so disturbing.

Like winning the lottery

"Reality was my model," explained director Katrin Gebbe.

She had read in the newspaper about a couple who had kept a mentally handicapped boy in their basement for months in 2009, torturing him to death. Having just completed her degree at the Hamburg Media School, she was on the lookout for material for her first feature film.

Together with producer Verena Graefe-Höft, who had also studied in Hamburg, Gebbe tackled the seemingly impossible project: a film without a classic love story, an uncomfortable topic and relatively unknown actors.

It seemed destined for failure. But then, a miracle happened: The low-budget production was invited to Cannes - to one of the most renowned film festivals in the world. It is the only German film included on the official program.

"It's so fantastic, especially for me as a young filmmaker," exclaimed Katrin Gebbe. "It feels like I've won the lottery!"

Playground for creativity

"Tore tanzt" is part of the Un Certain Regard side series, which highlights experimental works that aren't part of mainstream cinema. These are creative films - by both novice and veteran directors - that play with form and tackle challenging topics.

"The Bling Ring," a new film by Sofia Coppola, is also running in Un Certain Regard. Reality seems to be more exciting than fiction this year on the Côte d'Azur: Coppola's storyline is likewise based on real events. It's about a group of girls who break into stars' mansions in Beverly Hills and ultimately get caught.

Katrin Gebbe's oeuvre will have to hold its own next to 17 other features in the Un Certain Regard series. But her clear visual language and subtle storytelling are her strengths.

"Of course it's also about violence," explained the 30-year-old director. "But this brutality is not imbedded in a genre, like in a horror film, for example. It comes out of everyday life. And that's what makes it all so haunting."

It would have been easy to let the figure of the naïve Christian degenerate into a caricature. But Gebbe doesn't put faith on a pedestal, nor does she condemn evil. Rather, bit by bit, she uncovers doubts and insecurities on both sides of faith's fence. And she does so in a series of painful images whose hurt she lets resonate.

Such raw reality is rare on Cannes' star-studded Croisette.