"Sometime late in 1598, Christopher Marlowe, the brilliant poet and playwright, wrote a scathing letter to his patron and protector, Sir Thomas Walsingham. Accusing him of having an "inconstant mind", Marlowe threatened to "set down a story of faults concealed" and challenged him to "hate me when thou wilt." Sir Thomas, veteran of his "uncle's" anti-Catholic intelligence service, would immediately have recognized the danger. Marlowe, who most of...