Demons of Urban Reform essays an answer to the question of why the diabolic witchcraft concept was adopted into ordinary criminal justice and what effects it had thereafter. Lucerne and Basel, two Swiss-German city states that received and accommodated the diabolic witch concept in the mid-fifteenth century, are examined alongside Franconian Nuremberg, where the diabolic witch concept was soundly rejected. Basel, like Nuremberg, ultimately rejected the diabolic witch concept and the mass trials that it inspired elsewhere. In Lucerne, however, witch trials had a transformative effect on criminal justice, and early witch hunts in the late fifteenth century presaged even greater conflagrations a century later. Laura Stokes roots the analysis of witch trials in the quotidian proceedings of the secular courts she examines, offering evidence for the importance of social control in pre-Reformation cities and the reciprocal relationship between developments in criminal justice and judicial concerns over witchcraft.