The stories of the Penderwick siblings, Rosalind, Skye, Jane, and Batty and all of their adventures, and they also get two siblings (Lydia and Ben) and a bestie a.k.a "Honorary Penderwick" whose name is Jeffrey, and it's like a five book series about all the weird stuff these kids get up to. The second book is probably my favorite one in the series, I have them all now :).