There are movies -- too many to count -- that promise escape from the messy realities of our lives. And then there's "Everyone Else," writer/director Maren Ade's suitably grueling study of a relationship teetering on the knife-edge of collapse.

Plot-wise, what happens to the vacationing couple in this German answer to John Cassavetes couldn't fill up a cocktail napkin. But Ade's emotional incidents stretch infinitely wide from the start and never recede. Surely not for the faint of heart, "Everyone Else" is one of the most difficult -- and rewarding -- films of the year, and one of the best.

With only her second feature (the first was the similarly intense "The Forest for the Trees"), the thirtysomething Ade has placed her bid for inclusion among the cinema's reigning masters of the anti-romance. In that screening room in the sky, Cassavetes is nodding in agreement with Ade that love hurts -- when it exists at all.

Young, scantily clad and easily distracted, Chris (Lars Eidinger) and Gitti (Birgit Minichmayr) are trying and largely failing to enjoy their week together at his parents' villa on the Mediterranean island of Sardinia. The extraordinarily lush scenery is plenty inviting, but everyday emotions keep getting in the way.

In between lovemaking sessions, Chris, a struggling architect, and Gitti, a high-strung publicist, have a dangerous habit of talking. She: "I would like to be different for you." He: "For once, can we please talk in a normal way?"

Normal or not, "I love you" isn't a phrase in Chris' lexicon, and Gitti knows it. Gradually it becomes clear that there's an inequality of affection in this couple -- as there is in most couples, onscreen or off. Somehow the pair's dinner companions, Hans (Hans-Jochen Wagner) and his pregnant wife, Sana (Nicole Marischka), maintain a persuasive illusion of perfection, which naturally exacerbates the friction between abundantly flawed Gitti and Chris.

The experience of "Everyone Else" is like eavesdropping on strangers who fast become familiar. Ade dares to present us with characters that are at once recognizable and largely unpleasant. Chris appears annoyingly passive and noncommittal, while Gitti seems cloying and overly fragile. Who's to blame? Both and neither, of course.

The increasing distance between the two lovers is brilliantly captured in a long hiking scene that places Gitti and Chris on opposite edges of the frame, an expanse of mountainous terrain between them. Although Ade mainly suggests that this interpersonal chasm cannot be bridged, the film's astonishing final minutes offer a faint hint of connection -- or arguably so, anyway.

Like Cassavetes' "A Woman Under the Influence," Ade's film is as unpredictable and ambiguous as it is raw. In other words, "Everyone Else" isn't for everyone, especially not those who prefer to keep their work at the office and their discomfort in private. That's the thing about the best arthouse movies -- and the best relationships, too. No one ever said they were going to be easy.