Available on DVD: “The Forgiveness of Blood”

Imagine you’re a teenage boy. You’re on Facebook, you text your friends around the clock, you dream of opening a gaming arcade. You kick a soccer ball around after school and think of all the things you can’t bring yourself to say to that girl in your classroom.

Now imagine you’re a teenage boy in Albania. You used to have all of the above but now you can’t leave your house, because your family is involved in a blood feud with another family, and you’ll get shot if you walk out the door.

In Joshua Marston’s coolly furious The Forgiveness of Blood, that teenage boy is Nik (Tristan Halilaj), marooned somewhere between the 21st century and the 15th. Tall, lanky, with dark eyes that deepen over the course of the film, Nik has every adolescent’s disdain for the customs of his parents’ world. That this renders him the film’s only functioning adult is the bleak joke at the center of the tale. Or it would be if anyone were laughing.

Marston is the very rare American filmmaker who’s interested in what happens elsewhere on the planet. He doesn’t make foreign films so much as human films: His fine 2004 debut, Maria Full of Grace, was about a pregnant Colombian teenager (Catalina Sandino Moreno) who becomes a drug mule. For his second movie, he hops across the globe to find another kid doing what he can to make his life comprehensible.

The modern and the medieval coexist in The Forgiveness of Blood. Nik’s father, Mark (Refet Abazi), delivers bread to his village in a horse-drawn wagon; every day he moves stones to take a shortcut across a neighbor’s field, and every day the neighbor moves them right back. Push comes to shove, shove leads to stabbing, and the vendetta is on, governed by the traditional Albanian set of laws known as the Kanun, whose roots go back to the Bronze Age. With Mark in hiding, Nik’s sister Rudina (Sindi Lacej) takes over the increasingly risky delivery route, while Nik and his little brother (Luan Jaha) — by tradition, the next targets for revenge — are effectively under open-ended house arrest.

The Kanun is administered by old men, and they take their time. As Nik sees his youth slide through his hands — his best friend brings a new iPhone over, with videos of schoolmates sending their regards — he’s simultaneously powerless and desperate to act. He builds a weight room on the roof, surrounded by cinder-block walls to protect himself from the occasional bullet. He proposes eminently practical mediation ventures. Eventually he slips out after dark, a village ghost stuck between epochs.

The Forgiveness of Blood works as a subtle but insistent metaphor for a modern generation trapped by the shibboleths of their elders. It applies to Albania specifically and civilization in general, and the film would speak as loudly to American teenagers if they knew it was out there. At the same time, Marston and his co-writer Andamion Murataj dramatize unique portraits of coping and crumbling. Rudina is as resourceful as her brother in thinking outside her society’s cramped box, and the movie’s suspense lies in whether their pragmatic idealism will have an effect or turn to cynicism.

At times, the film purposely avoids melodramatics — the murder itself takes place offscreen, its particulars beside the point — and there are moments, too, when the filmmaker seems stuck outside the cultural door looking in. Marston’s a miniaturist even when The Forgiveness of Blood calls out for larger gestures, and you occasionally sense a more bruising, compelling movie lurking behind this one. His heart is really with the wider world his youthful hero already belongs to, and his film simply wonders what it takes for a boy to walk out into it.