Greg and Jill are assigned a treasure hunt as part of a class project. The setting for the hunt is the mysterious and intriguing Bannerman Island located in New York's Hudson River. The remains of castles built by arms and munitions businessman Francis Bannerman provide a looming, almost eerie backdrop for this piece of children's historical fiction.Along the way, Jill and Greg encounter a most unusual woman. Is she real? Is she magical?Their journey...