Geraldine Woolkins has at last become a middle mouse, but navigating the waters of middle-mouse life isn’t easy. Her younger brother irritates her, her sparrow friend Penelope neglects her, and an elder mouse friend is becoming forgetful, making the entire Woolkins family anxious.

Everything is changing. And when Geraldine discovers that the best treasures of spring—fragrant spring flowers, a pond created by spring rainstorms—will one day disappear, she is heartbroken. Does nothing last forever? Does everything good change or fade?

Ten more stories follow the Woolkins mouse family—Papa, Mama, Geraldine, and Button—from April, a time of blossoming, to June, the month of long days.