Georg Hoffmann (TV actor Matthias Brandt) is a level-headed cop who's liked by his colleagues and maintains the facade of a happy marriage with Anna (Trauttmansdorff) and their two grown kids, Lukas (Pablo Ben-Yakov) and Marie (Anna Brass). But the couple's home life is like walking on eggshells.

Anna, a primary school teacher, is a dark well of self-pity, whose neat, efficient front can suddenly change into that of a screaming Harpie. Marie is the only one whom Anna will really listen to but is close to the end of her tether. Lukas wants to quit college to become a cook but no one dares tells mom.

Georg tolerates Anna's explosions of verbal (and increasingly physical) abuse with endless stoicism -- apparently born from his true love for her, though he does flirt with the idea of an affair with a younger woman. When it's announced that Georg is due to get a promotion, the pin slips out of Anna's grenade.

Trauttmansdorff makes the best of her part as written, with scary eyes that can change from loving to mad in a split-second, but thesp is still hobbled by a script that doesn't fully explain her psychosis. Though dominated by condescending parents, and endlessly frustrated by the refusal of Georg (whom she dubs "a loser") to fight back, she still comes across more as a medical than an emotional case. Her unilateral decision to "foster" a problem child -- never properly developed by the script -- appears as just one more loopy decision rather than a naturally evolving way of gaining respect.

In the circumstances, Georg is the more abused character; but pic makes him largely a milquetoast bystander to Anna's tantrums than a man who should be at the end of his tether, primed to retaliate at any moment. Lack of dramatic give-and-take between the two protags turns the film into a what's-the-matter-with-Anna rondo, dominated by Trauttmansdorff's perf, rather than a genuinely escalating family drama. Kids' roles are especially underwritten.

Some of the best moments are when Bonner injects black comedy into the couple's relationship -- especially one sequence where Georg comes home to find Anna brazenly shagging his colleague, Michael (Wotan Wilke Moehring, good), on the couch. But these moments are fleeting, further adding to the pic's problems with tone.

Tech credits are functional, with wintry, TV-style lensing. Absence of music also reinforces the small-screen feel.

Camera (Fujicolor), Bernhard Keller; editor, Stefan Stabenow; art director, Tim Pannen; costumes, Frauke Firl; sound (Dolby Digital), Martin Witte; sound designers, Rainer Heesch, Tobias Fleig; assistant director, Friedemann Roll; casting, Susanne Ritter. Reviewed at Cannes Film Festival (Directors' Fortnight), May 20, 2007. Running time: 100 MIN.