Sisters Delphine and Muriel Coulin make a beautiful, but somewhat gloomy film adaptation of a French novel about the helplessness of a loving father when he is confronted with the right-wing radicalization of his son.

If you're one of those people whose first instinct in cases of youth violence is to blame the parents, "The Quiet Son," the new title from directors Delphine and Muriel Coulin ("17 Girls") that rivals Venice , has a valuable perspective. It tells the credible, somber story of a 22-year-old Frenchman caught up in right-wing street politics, exclusively from the perspective of his loving but incomprehensible father. If, however, you believe the problem is more complex than simple parental neglect, this solid, straightforward film has less to offer, since it poses and rehashes the problem of the growing, increasingly aggressive alt-right sympathies among young, working-class people without offering any new or particularly useful insights.

The Coulin sisters have adapted Laurent Petitmangin's novel "Ce qu'il faut de nuit." The film's main attraction, aside from the headline-grabbing current events, is Vincent Lindon (who has been cast so often as a laborer that he could confidently launch his own line of fluorescent jackets and sustainable workwear), who once again makes the most of a gruffly likeable average role. Lindon plays railroad repairman Pierre, a father who has raised two sons by himself after their mother died when they were boys. He paints a thoroughly convincing portrait of Pierre's arid fear of gradually losing one of his own to an ideology that he, as a Frenchman of a age raised in the aftermath of May '68, cannot even understand.

The sons form a credible if somewhat formulaic dichotomy between bookish, Sorbonne-bound Louis (Stephan Crepon) and athletic, engineering-school dropout Fus (Benjamin Voisin), a nickname short for "Fussball" he picked up as a soccer-mad kid. That it has German overtones is unsurprising; the family lives in France's historically contentious Lorraine region, which has its own proud regional identity, making its inhabitants ripe targets for anti-immigration rhetoric on two different levels. "You can grow up to be French," Fus says during a testy exchange with his father, "but you're born a Lorrainer."