Claude Lanzmann’s 9-hour-and-23-minute documentary epic is made up of interviews with people who have knowledge of the Nazi extermination centers—whether as slave laborers, railroad workers, technicians, bureaucrats, or just onlookers. The film has fine, painful moments, and it’s widely regarded as a masterpiece. But some may feel that it lacks the moral complexity of a great work, and may also find it logy and diffuse, and exhausting right from the start.