Movement at the Surface of a Rain Barrel

Case overview

Nia Robinson is closing up the yard at dusk when she notices a faint movement at the surface of the rain barrel behind the shed. The air is still. A leaf drifts near the rim, then the movement appears again. Her nephew Cal says he saw it yesterday too, but only after the warm week. Nia does not know whether the barrel has become a small mystery or just a place where yesterday's weather is still showing. They set a chair by the fence and watch without stirring the water. Then Nia begins to compare what she sees with the other containers in the yard, the lid position, and the last time anyone used the barrel. The case begins with an ordinary backyard detail and a question about which observation will turn it into a pattern.