This case study describes the use of narrative therapy with a mother and a foster child who was also her nephew. Primarily through the use of the narrative therapy technique of “externalization”, the therapist was able to help the mother and child overcome a crisis that was threatening the foster care arrangement. Over a period of eight sessions, the mother and foster son worked to separate him from the externalized problem of “avarice,” which had been causing him to steal and lie. As the mother moved beyond her problem-saturated stories, the foster son’s problematic behavior disappeared, and positive interactions between them increased. This case illustrates the usefulness of narrative therapy in working with families, even in highly conflictual foster care settings.