From his rapid-fire stand-up comedy riffs to his breakout role in Mork & Mindy and his powerful Academy Award-winning performance in Good Will Hunting, Robin Williams was an innovative actor and comedian. He often came across as a man possessed, holding forth on culture, politics, and personal revelation with mercurial, tongue-twisting intensity as he inhabited and shed one character after another. In his comedy and in celebrated films like Dead Poets Society, Good Morning, Vietnam, The Fisher King, Aladdin, and Mrs. Doubtfire, Williams showcased his gift for improvisation, bringing his characters to life and using humor to seek deeper truths. Culture reporter Dave Itzkoff shows how Williams also struggled mightily with addiction and depression and with a debilitating condition at the end of his life that affected him in ways his fans never knew. Drawing on more than a hundred original interviews with family, friends, and colleagues, as well as extensive archival research, Itzkoff provides a portrait of a performer whose work touched so many of our lives.