Maria teaches a class of ten-year-olds at a woefully underfunded school, doing her best against the odds. One pupil, foul-mouthed and disruptive, is derailing the whole class. After he starts a violent fight, Maria snaps, kidnapping him and locking him in her basement. She initially regrets her impulsive decision, but the rest of the class starts flourishing, staff and parents are delighted, and Maria finds herself trapped by her own solution. Saoirse Ronan stars in this black comedy blending satire, suspense and social commentary.