Only the most obstreperous delinquent could fail to be charmed by Monsieur Lazhar, in which an Algerian refugee plays ramshackle Mary Poppins to the kids at a Montreal primary. This sweet, soulful drama plays out to the scrape of desks and the echo of voices, and showcases a glorious performance from Mohamed Fellag as the substitute teacher who is not quite what he claims. Lazhar gatecrashes the school in the wake of a tragedy. He flounders, he flourishes and is eventually found out. There is just time to deliver one final, moving life lesson before the bell sounds, and the past rolls in to claim him.