On May 5, 1945, German U-boat 853 went down east of Block Island after evading capture for nearly twelve hours. Local legend fills the sunken submarine with a fortune in gold bullion, diamonds, and mercury meant to finance a new life for Nazi war criminals in America. History or legend? The truth would remain hidden for over half a century. While going through their late grandmother's possessions, Dan, Tom, and Kate Morgan uncover eight messages encrypted...