Book 1


Book 2

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.

Book 3


Book 4


Book 5


Book 6


Book 7


Book 8


Book 9


Book 10


Book 11


Book 12


Book 13


Book 14


Book 14


Book 15


Book 16


Book 17

While visiting an old mansion, the Aldens investigate the possibility that it may be haunted.

Book 18


Book 19