From the publisher
Aunt Eloise invites Nancy, Bess, and George to a cabin near Cooperstown, New York for a chance to solve the mystery of a woman who glides across the water. Nancy becomes involved in a vacation hoax because she resembles a woman involved in the hoax. A mysterious green sorcerer who appears in the woods and an lost treasure involving the gliding woman lead Nancy to help uncover a cleverly concealed operation in the woods.