On April 30, 1971 in New York City’s Town Hall, a group of feminist luminaries gathered for a public debate on Women’s Liberation with novelist Norman Mailer, hot on the heels of his controversial essay “The Prisoner of Sex.” Featuring renowned critic Diana Trilling, Village Voice columnist Jill Johnston and a razor-sharp Germaine Greer, the now-infamous firestorm—a flash point in second-wave feminism—was immortalized by Pennebaker and collaborator Chris Hegedus. While the audience, which included Susan Sontag and Betty Friedan, stays remarkably calm, watch as the podium breaks out in a very lively and heated discussion that still resonates today.