When the three younger Penderwick sisters go to Maine with Aunt Claire and are separated from oldest sister Rosalind for the first time in their lives, an uncertain Skye is left in charge as the OAP--oldest available Penderwick.

On the last night of summer, Emma and her Maine game warden father rescue a small domestic rabbit stuck in a fence; the very next day Emma starts fifth grade after years of being home schooled, excited and apprehensive about making new friends, but she is paired with Jack, a hyperactive boy, who does not seem to fit in with anyone--except that they share a love of animals, which draws them together, because of the rabbit.