The Treasure in the Royal Tower
Carolyn Keene
 Nancy takes a vacation in Wisconsin when the library of the place she is vacationing at is vandalized. Nancy, along with her friends George Fayne and Bess Marvin, must survive an unknown assailant while discovering the secret passageway's inside of an old castle. Later, Treasure in the Royal Tower was made into a Computer (PC) Game where you can play as Nancy and find Marie Antoinette's tower.