While vacationing with their widowed father in the Berkshire Mountains, four young sisters, ages four through twelve, share adventures with a local boy, much to the dismay of his snobbish mother.

As spring arrives on Gardam Street, there are surprises in store for each Penderwick, from neighbor Nick Geiger's expected return from the war to Batty's new dog-walking business, but her plans to use her profits to surprise her family on her eleventh birthday go astray.