How did people in ancient Mesopotamia respond to illness and misfortune that they suspected to be the consequence of their own transgressive actions? Some people could consult an exorcist (āšipu), a ritual and medical specialist whose expertise allowed them to determine the causes of their patients’ suffering, reconcile them with the gods, and restore their health and wellbeing. By examining the theoretical background of relevant ritual texts, this book reveals what the exorcist’s understanding of concepts such as sin, self-curse, and divine punishment can tell us about ideas like ethics, guilt, and atonement in Mesopotamian society and religion.