Since her death, Sylvia Plath (1932–1963) has become an endless source of fascination for a wide audience ranging from readers of The Bell Jar, her semiautobiographical novel, to her groundbreaking poetry as exemplified by Ariel. Beyond her writing, however, interest in Plath has also been fueled in part by the tragic nature of her death. As a result, a steady stream of biographies of Plath have appeared over the last fifty-five years that mainly focus on her death or contain projections of an array of points of view about the writer. Until now, little sustained attention has been paid to the influences on Plath’s life and work. What movies did she watch? Which books did she read? How did media shape her worldview? In this meticulously researched biography, Carl Rollyson explores the intricate web of literature, cinema, spirituality, psychology, and popular culture that profoundly influenced Plath's life and writing. At the heart of this biography is a compelling exploration of William Sheldon’s seminal work, Psychology and the Promethean Will, which Plath devoured in her quest for self-discovery and understanding. Through Plath’s intense study of this work, readers gain unprecedented access to Plath's innermost thoughts, her therapeutic treatments, and the overarching worldview that fueled her creative genius. Through Sheldon as well as Plath’s other influences, Rollyson offers a captivating survey of the symbiotic relationship between an artist and the world around her and offers readers new insights into the enigmatic mind of one of the most important writers of the twentieth century.