This paper is a narrative account of a critical classroom episode in the life of a beginning secondary science teacher. Emphasis is placed on a beginning science teacher's prior knowledge of effective science instruction and is used to guide on-going classroom practices to facilitate student learning. The story is created from classroom observations of a secondary science teacher intern, formal and informal interviews with the teacher intern, and a critical autobiography describing his views on science, knowledge, teaching, and learning. The story revolves around an issue the teacher is confronted with related to poor laboratory report grades. The issue is resolved by the teacher's decision to conduct a science process lesson in which students re-interpret their laboratory findings and present their results before the entire class. (Author/DDR)