This essay treats Freud's “Observations on Transference-Love,” written a hundred years ago, as the quintessential psychoanalytic document, defining the clinical setup, charting its dangers, and providing ethical precepts for guiding treatment. Above all, in the context of those ethical questions, Freud's paper confronts the immense power and necessary strangeness of the transference—that form of love, or erotic bond, that fuels the healing process. The “potion”—an artificial yet powerfully real attachment—is the agent of a temporary induced blindness that gives access to a region otherwise inaccessible. A dream is presented to demonstrate that process. Freud, in describing this incendiary arrangement, likens it to a fire in a theater. The fire, the author proposes, is in the script.