The Aldens have new neighbors, and they're helping them build a tree house! From up high they can see things they hadn't seen before. There's a strange round window on the house next door that's been hidden by trees - but nobody can find the window from inside the attic. Does their neighbor's old house have a secret?
About the Author
Gertrude Chandler Warner was born in 1890 in Putnam, Connecticut, where she taught school and wrote The Boxcar Children because she had often imagined how delightful it would be to live in a caboose or freight car. Encouraged by the book's success, she went on to write eighteen more stories about the Alden children.