Ty discovers an entire township chained to a sunken submarine, its inhabitants condemned to an icy underwater grave. It's only the first clue to a mystery that has claimed hundreds of lives and stands to claim two more -- - lives very precious to Ty and his Topsider ally, Gemma.

"It may be autumn on Cranberry Island, Maine. but things are heating up for innkeeper Natalie Barnes - and not just because of the cranberry scones in the oven. When a research team discovers the remains of a long-missing German U-Boat just offshore, the Gray Whale Inn becomes the center of operations for the eccentric multmillionaire funding the team. But the excitement over the discovery is soon dampened when something else turns up next to the...