This article introduces the Journal of Personality's special issue on the life voyage of Dodge Morgan who, in 1986 at the age of 54, sailed solo around the world in 150 days. Before the voyage, Morgan agreed to participate in an intensive psychological case study, the data for which provide the focus for this special issue. William Nasby and Nancy W. Read have organized the vast array of psychological data obtained from Morgan and produced a complex and illuminating interpretation of his life, drawing liberally from the five-factor trait model of personality and the life-story model of adult identity. This introduction provides a historical and intellectual context for Nasby and Read's study by considering the various ways in which personality psychologists have employed the case study in research and examining the many conceptual and methodological problems and possibilities that arise in the psychological study of the single case.