Focusing on the recurring metaphor of Medusa's head, The Medusa Effect examines images of horror in texts by Sigmund Freud, Friedrich Nietzsche, and a series of Victorian artists and critics writing about aesthetics. Through nuanced and innovative readings of canonical works by Freud, Nietzsche, Dante Gabriel Rossetti, Walter Pater, A. C. Swinburne, and George Eliot, Thomas Albrecht demonstrates the twofold nature of these writers' images of horror. On the one hand, the analysis illuminates how the representation of something seen as horrifying—for instance, a disturbing work of art, an existential insight, or a recognition of the fundamental inaccessibility of another person's consciousness—can serve a protective purpose, to defend the writer in some way against the horror he or she encounters. On the other hand, the representations themselves can be a potential threat—epistemologically unreliable, for instance, or illusory, deceptive, fundamentally unstable, and potentially dangerous to the writers. Through a psychoanalytically informed literary analysis, The Medusa Effect explores crucial ethical and epistemological questions of Victorian aesthetics, as well as underexamined complexities of the mechanisms of Victorian literary representation.