The movement of sand dunes in the desert is an emergent process; the overall movement of a dune is influenced both by the random interactions among individual sand particles and by the process of wind adding and subtracting sand. People often misconstrued emergent processes as deterministic processes containing central causality. I present a case study of how one person, an adult, who was not an expert in physics, articulated and refined her explanation of the movement of sand dunes. She began with centralized causality but ended with an explanation containing the cogent emergent ideas. This case study is noteworthy in exemplifying the dynamic process of generating an explanation. The interviewee went through four different explanations at three different levels (macro, micro and mid-level) and concluded with an explanation that simultaneously addressed the movement of sand dunes at all three levels.