Tough medicine.

Tough medicine.

Attention must be paid when a film as formally audacious as The Tribe comes along.

Debut feature director Myroslav Slaboshpytskiy made it with an all-deaf cast and chose to forgo narration and subtitles. Even knowledge of American Sign Language won’t help, since the action takes place in the Ukraine, though the untrained actors communicate just fine through their gestures and body movements. The central character, Sergey (Grigoriy Fesenko), kicks the story into motion when he arrives at a boarding school at which the students make all their own rules, and the teachers either don’t know or don’t care…