This chapter examines the case of an impostor. Within the general plot of disguise and misprision there may be a special place for the impostor, the willful trickster who would have others believe he or she is another. The version of the impostor most familiar in the popular imagination may be the spy, especially the double agent. The spy offers a version of one's worst fears about the instability of one's self, one's proteanism as a certain hollowness. Meanwhile, psychoanalyst Helene Deutsch became interested in what she called “as-if” personalities who only tentatively inhabit one identity. Ultimately, imposture allows one to live out a life according to one's fantasies without attributing this life to one's self, since one knows one's “true” identity is not up to the fantasy.