Shylock, the Jewish moneylender in The Merchant of Venice who famously demands a pound of flesh as security for a loan to his antisemitic tormentors, is one of Shakespeare's most complex and idiosyncratic characters. With his unsettling eloquence and his varying voices of protest, play, rage, and refusal, Shylock remains a source of perennial fascination. What explains the strange and enduring force of this character, so unlike that of any other in Shakespeare's plays? This book posits that the figure of Shylock is so powerful because he is the voice of Shakespeare himself. It argues that Shylock is a breakthrough for Shakespeare the playwright, an early realization of the Bard's power to create dramatic voices that speak for hidden, unconscious, even inhuman impulses—characters larger than the plays that contain them and ready to escape the author's control. Shylock is also a mask for Shakespeare's own need, rage, vulnerability, and generosity, giving form to his ambition as an author and his uncertain bond with the audience. The vision of Shylock as Shakespeare's covert double as given in this book leads to a probing analysis of the character's peculiar isolation, ambivalence, opacity, and dark humor. Addressing the broader resonance of Shylock, both historical and artistic, the book examines the character's hold on later readers and writers, including Heinrich Heine and Philip Roth, suggesting that Shylock mirrors the ambiguous states of Jewishness in modernity.