Ten-year-old Ryan Wolf has a secret: he is the protector of the Eigenoids, a group of creatures tinier than dust particles who live in a box given to Ryan by his grandfather. The Eigenoids use their magic to shrink Ryan down to their size in order to help him learn about the world around him.

During a baseball game, Ryan gets a splinter in his finger. After hearing about how his grandfather lost part of a finger due to an infection from a splinter, Ryan worries that the same thing will happen to him. In order to help, the Eigenoids transform him into a white blood cell so...