Pity the filmgoer who expects the Dardenne brothers when meeting the brothers of “The Ardennes,” a Belgian Christmas story in which sibling betrayal is resolved in increasingly brutal fashion. Closer to the absurdism of Martin McDonagh (“In Bruges”) than to some of first-time feature helmer Robin Pront’s acknowledged models (Tarantino, the Coens), the movie is slow to reveal its nastier elements, appearing for two-thirds of its running time to be merely an absorbing, low-key drama about a troubled family reuniting after one son’s release from prison. Given an abrupt, ill-modulated shift into Grand Guignol territory in its last third, this off-putting debut seems unlikely to be a breakout on the order of Oscar nominee “Bullhead,” with which it shares several key collaborators.
An in medias res prologue quickly establishes that Kenny (Kevin Janssens) is serving time for a botched crime, having refused to rat out his accomplices: his girlfriend, Sylvie (Veerle Baetens), and his brother, Dave (Jeroen Perceval, who co-wrote the script, adapting his own play with Pront). Flash forward four years to Kenny’s release. Dave and Sylvie are now on the straight and narrow, and also a couple — something that Dave, claiming to have a separate girlfriend, can’t bring himself to admit to his still-smitten brother.
Sylvie is pregnant, and she and Dave are trying to keep things together. But Kenny, goading his brother into drinking again, has a penchant for making trouble. In a threatening confrontation, he shows up at Sylvie’s support group to ask why he hasn’t heard from her in two years (the time she’s been clean). Dave gets Kenny a job working alongside him at a car wash, where a creatively staged brawl sequence on the cleaning line offers a hint of the second half’s escalating violence. Kenny also grows paranoid over Sylvie’s boss (rapper Rachid “Appa” El Ghazaoui) at a club.
Initially, “The Ardennes” appears to be a fraught family drama set against a wintry-gray Antwerp backdrop. (Belgium’s Ardennes region, the sylvan location of the film’s climax, is where Dave and Kenny used to go for family weekend getaways.) But about 50 minutes in, as Kenny seeks help with a cover-up from his unstable former cellmate, Stef (Jan Bijvoet, of Alex van Warmerdam’s “Borgman”), “The Ardennes” shoots for the full “Fargo” and becomes another movie entirely — the sort of darkly comic, take-no-prisoners genre piece in which dismembered body parts and a sudden ostrich attack are par for the course.
The climax quickens the film’s pulse but doesn’t exactly grow organically from what’s proceeded it. Pront and Perceval strain mightily to maintain the tension between the leads (again and again, Dave declines to confess his relationship with Sylvie to his brother) but never raise the stakes to a point that portends the gruesome resolution.
Robrecht Heyvaert’s wintry cinematography augments the grim ambience of the locations; the movie is hardly a tourism ad for the Ardennes region. A techno score sometimes evokes a less bass-y John Carpenter track but more often just acts to signal empty edginess.