Riley and family fly north to Churchill, Canada, to watch polar bears hunt seals from the ice of the Hudson Bay. There's just one problem: no ice! For polar bears, no ice means no seals, and without food, the bears can quickly become hungry, weak and dangerous! It's a race against time as everyone searches for clues to this puzzling climate mystery. Will the ice freeze in time-or at all? And will the polar bears finally eat again?