The Quest of the Missing Map
Carolyn Keene
 Nancy investigates a small ship cottage at the Chatham estate and discovers a connection between the mysterious occurrences at the cottage and an island where a lost treasure is said to be buried. With one half of a map, Nancy sets out to find a missing twin brother who holds the other half. The mystery becomes dangerous when an assailant hears about the treasure and is determined to push Nancy off the trail.