The Alden children suspect that the other guests are somehow involved when things begin to disappear at the bed and breakfast where they are staying in Washington, D.C.

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.