Carolyn Keene Nancy Drew Mystery Collection 10 Books set. (Books 41-50)
The Clue of the Whistling Bagpipes.
The Phantom of Pine Hill.
The Mystery of the 99 Steps.
The Clue in the Crossword Cipher.
The Spider Sapphire Mystery.
The Invisible Intruder.
The Mysterious Mannequin.
The Crooked Banister.
The Secret of Mirror Bay.
The Double Jinx Mystery.