The film captures the tumultuous end of the 1960s by chronicling one of the most notorious events in rock history, the ill-fated free concert by the Rolling Stones at the Altamont Speedway in California. The documentary style footage showcases the preparation and the journey of the Rolling Stones as they embark on their 1969 US tour, leading up to the Altamont concert. It offers a raw and candid look at the band's interactions and performances, juxtaposed with scenes of the eager, often chaotic audience that underscores the cultural landscape of the era.

The concert itself, attended by a massive throng of people, unfolds with increasing tension, as the inadequately planned event quickly spirals out of control. Security for the event, handled by the Hells Angels motorcycle gang, becomes violent, and the atmosphere grows heavy with the sense of danger. The film presents an unflinching view of the breakdown of peace and love ideals of the 1960s, capturing on camera the critical moments that symbolize the end of an era in rock and roll history. As the concert progresses, the sense of order collapses, with the chaos mirroring the wider social and cultural upheaval of the time.