We undertook this case study to examine the transition from university student to student teacher of an elementary science teaching enthusiast, Marie. The purpose of the study was to understand how Marie coped with constraints to her science teaching that she perceived within the school culture. We analyzed the data: (a) field notes taken during classroom observations, (b) transcripts of interviews with Marie, her cooperating teachers, students, and the principal, and (c) documents including lesson plans, handouts, tests, and methods course products, by using analytic induction to develop categories. We also generated assertions and tested their viability by triangulating the data sources. From the data we induced a number of patterns that Marie knowingly and unknowingly used to address perceived constraints such as supervisor expectations and inadequacy of equipment and curriculum. In coping with these constraints, Marie tried to saturate the curriculum with science, even finding additional time in the school week to conduct science lessons. At times she complied with perceived expectations, but typically she modified the constraining factor to produce a suitable result. Furthermore she served as a catalyst for science among her fellow teachers. Her strategies are somewhat unique for a beginner, but may be influenced by her position as science enthusiast and by the traditionally low status of science in the elementary school curriculum.