By December 1969, the 60s had already delivered moon landings, assassinations, protests, and a total rewrite of what pop culture could look like. But when The Rolling Stones rolled into Northern California for a free show at Altamont Speedway, what was supposed to be a triumphant celebration curdled into catastrophe. By the end of the night, a young man was dead—and the flower-powered optimism of the era felt like it had slipped through everyone’s fingers.