When an apple falls on his head, Newton the squirrel begins to wonder how the world works. Listening in on a lesson about the force of gravity, he decides to try his own experiments with the help of his sister, Curie. Learning to make simple machines, they discover that science is for everyone -- even squirrels. And when a birds' nest falls out of a nearby tree, only Newton and Curie, using their inventions and quick scientific thinking, can save the day! Includes author's notes and glossary of scientific terms.