As a documentarian, Kates has the luxury of choosing from an embarrassment of riches. Sontag was one of the most photographed and filmed women of the twentieth century, and there is much footage of her, both as a glamorous young writer and as an older provocateur. Kates is also gifted with the presence of colorful interviewees, including many of Sontag’s high-profile ex-lovers, from dancer Lucinda Childs to photographer Annie Leibovitz.

Throughout, Sontag’s avid curiosity—a curiosity that led her to everything from philosophy to playwriting to political activism—is apparent. In one interview, she remembers being told by her stepfather, “Sue, if you read so much, you’ll never get married,” a warning she happily ignored. Though not the most ardent feminist (“She was a feminist who found most women wanting,” says writer Sigrid Nuñez), Sontag advanced women’s rights in her own way, by proving that gender was no barrier to achievement or being taken seriously.

As Kates delves into her biography, we get glimpses of darkness at the heart of Sontag’s creativity. Closeted throughout her life, she writes in a journal that “my desire to write is connected to my homosexuality. I need the identity as a weapon to match the weapon that society has against me.” And, curiously for a women so often photographed, she admits that “being photographed I feel transfixed, trapped.” She was caught in the strange position of getting attention for an attractiveness that she felt shouldn’t be important.