It's spring in the Subarctic and the polar bears and tourists have left Churchill, Manitoba. Bear season may be over, but for wildlife filmmakers, scientists, and bear guides, a miraculous new story is about to begin. Mother bears and their cubs are emerging from their dens for the first time, after a half-year underground. It's a miraculous sight to witness, but for the mother and her cubs, it's just the beginning. They must now make a 70-mile trek to the coast of Hudson Bay, a journey threatened by hunger, blinding snowstorms, and wolves.