The movie is built around a freewheeling interview with King today, who unfurls the saga of her life. She’s 82 now, and the filmmakers frame her in a single head-on shot. She’s wearing fuchsia horn-rims and a teal athletic jacket, and what gives the documentary its unique pulse is that King has the energized articulation of a woman decades younger than her years. She’s warm and laceratingly honest, with a ripe sense of humor, and she speaks in rich percussive sound bites, which the filmmakers employ in a nearly musical way, cutting back and forth, often rapidly, between King’s words and clips of the story she’s telling. We feel like we’re inside her head, and the footage itself is extraordinary.