The Rolling Stones close out their 1969 American tour with a free concert at the Altamont Speedway, and the Maysles brothers' cameras are there when it goes wrong. The film builds toward that night in two directions at once: forward through the tour itself, with Mick Jagger and the band performing across arenas, and backward, as Jagger and drummer Charlie Watts sit in an editing room watching the Altamont footage played back to them, reacting in real time to what their concert became. The Hells Angels, hired as security for a few hundred dollars of beer, are on camera throughout, and the fatal stabbing of Meredith Hunter during the Stones' set is captured on film and shown, frame by frame, as evidence. Woodstock had happened four months earlier as proof that a generation could gather peacefully; this is the document of the counter-case. The Maysles' direct-cinema style, no narration, no talking-head hindsight, just the footage and the band's own stunned faces watching it, is what makes the film still unsettling.