This thesis examines a little-known hybrid genre popular in the late nineteenth and early twentieth centuries: psychic detective fiction. The stories that comprise this hybrid genre involve the rational investigation of supernatural phenomena. They have received relatively little critical attention due, in part, to their inability to fit comfortably in either the traditional “detective” or “ghost story” categories, in addition to the comparative obscurity of many of the writers. Typically, psychic detective narratives have been subsumed within the discourses of late Victorian “Gothic” criticism. Consequently they have been understood as manifestations of various forms of cultural anxiety because Gothic criticism is typically concerned with the transgression of boundaries and the anxieties associated with modernity. This thesis moves beyond the anxiety model of Gothic criticism by arguing that psychic detective fiction engages with ideas of progress, contemporary occult theories and the development of professionalisation at the turn of the century. While anxiety was certainly one response to the uncertainty and rapid change that is generally understood as characterising the late nineteenth and early twentieth centuries, so too was optimism, excitement regarding new possibilities and a fervent desire to bring about social improvement. In particular, this thesis focuses upon progressive ideas of social reform, collectivism, relativity, the synthesis of seemingly different “ways of knowing” and the possibilities offered by new fields of study such as the social sciences and psychical research. It is the sense of possibility, excitement, and faith in the ability to improve (both as individuals and as a society), that characterises psychic detective fiction. The detectives discussed are concerned with problem solving, attempting to bring about positive resolutions to supernatural problems, and providing assistance to those in need. In psychic detective fiction resolution and understanding is most often brought about through the merging of seemingly disparate elements and the transcending of binary oppositions, rather than the traditionally Gothic mode of reinstating former boundaries and enforcing the separation or elimination of the threatening force. Psychic detectives are more concerned with forging new paths than recovering the status quo.