To this volume on out-of-school STEM learning, we contribute an example of science. Our charge is to discuss what it means for children to be doing science and how educators can assess it. To that end, we’ve chosen an especially clear case. It happens to have taken place in school, but that shouldn’t matter for our purpose here; it’s the substance of the children’s reasoning that we’re assessing as the beginnings of science. We open with the case. We then articulate how it is an example of science, in particular of science as a pursuit. Finally we discuss what this view means for science