Invisible to humans exists a parallel world of mice, where young Jenny misses her cherished grandfather so much that she begins to see him everywhere. Jenny is as close to her grandfather as a small mouse can be. Grandfather shows Jenny how to button her buttons and how to write her name. He passes along to her the secrets of making the best lasagna in all of Boston. And during long, shared days at Revere Beach, Grandfather teaches Jenny the names of the seashells they find washed up on shore.