Loosely based on a real-life incident presented here as a last-act plot twist, The Lesson is a spare, stripped-to-essentials drama about economic stress and mounting desperation. The naturalistic style of the storytelling is stealthily enthralling, as is the lead performance by Margita Gosheva as a provincial Bulgarian schoolteacher who is slowly, inexorably driven to the edge by crushing debt. Early scenes recall Charles Bukowski’s warning about “the continuing series of small tragedies that send a man to the madhouse.” Later, a sequence that begins with Nadezhda’s car breaking down, and continues with the schoolteacher’s frantic rush to make a bank payment, is more suspenseful than most Hollywood thrillers. In the end, Gosheva overshadows everyone else onscreen with her portrayal of a desperate woman who only gradually reveals herself as fully capable of going to extremes.