This inquiry-based investigation focused on shadow measurement and the apparent movement of the Sun throughout the school year. Students would collect data about their shadows weekly. Toward the end of the year, students would then organize and interpret their data. The authors hoped they would discover that the angle of the Sun changes throughout the year, as witnessed by the changing length of their shadows. But what began as an investigation into shadows and measurement quickly moved into several hours of discussions and model-making into what causes the seasons--all due to theories that students had about what causes their shadow length to change throughout the fall, winter, and spring months. (Contains 2 figures.)