Since a large gap exists between the rhetoric of reform-minded teacher education and what actually transpires in student teachers' field experiences, this study sought to fill a gap in current scholarship which has yet to document how mentor teachers, conceptualized as school-based teacher educators, shape and conduct their work with student teachers assuming the role of full-year undergraduate interns. The purpose of this study was to explore mentor teachers' ways of being and knowing as they work with interns in a newly created, inquiry-oriented professional development school. This investigation uses case study methodology informed by both ethnographic and phenomenological perspectives. Using these lenses and data collected over an 18-month period, the stories of two mentor teachers are captured and analyzed. Three themes emerged within each case that characterized the unique work of each site-based teacher educator: teaching interns as teaching children, mentoring as decision making, and creating spaces as pedagogical tools. The three themes that shape the work of the first mentor offer insight into an artistic approach to mentoring. The three themes of the second case suggest an inquiry-oriented approach to mentoring. (Contains 40 references.) (Author/SM)