Mystery Behind the Wall (The Boxcar Children Mysteries #17)

#1 · The Boxcar Children (The Boxcar Children Mysteries Book 1) #5 · Mike's Mystery (The Boxcar Children Mysteries #5) #8 · The Lighthouse Mystery (The Boxcar Children Mysteries #8) #12 · Houseboat Mystery (The Boxcar Children Mysteries #12) #13 · Snowbound Mystery (The Boxcar Children Mysteries Book 13) #15 · Bicycle Mystery (The Boxcar Children Mysteries #15) #17 · Mystery Behind the Wall (The Boxcar Children Mysteries #17) #18 · The Bus Station Mystery (The Boxcar Children Mysteries #18) #19 · Benny Uncovers a Mystery (The Boxcar Children Mysteries #19) #21 · The Deserted Library Mystery (The Boxcar Children Mysteries Book 21) #24 · The Mystery of the Hidden Painting (The Boxcar Children Mysteries Book 24) #38 · The Mystery of the Purple Pool (The Boxcar Children Mysteries Book 38) #39 · The Ghost Ship Mystery (The Boxcar Children Mysteries Book 39)