335 books • 21 series
The Castle Mystery (Boxcar Children, #36) (Boxcar Children Mysteries, #36) (A Boxcar Children's Mystery)
The Pizza Mystery (Boxcar Children, #33) (Boxcar Children Mysteries, #33) (Box Car Kids Graphic Novel)
The Mystery of the Singing Ghost (Boxcar Children, #31) (Boxcar Children Mysteries, #31)
The Mystery of the Hidden Painting (Boxcar Children, #24) (Boxcar Children Mysteries, #24)