Polar bears are the largest land carnivores in the world. In the fall, 900 individuals gather along the Canadian coast, waiting for the annual sea ice to form so they can hunt. The polar bears may seem active, but their bodies are in a state of hibernation so they must call upon their unique ability to persevere in this harsh environment despite extended periods of fasting. Pregnant females fast for eight months a year during which time they give birth before emerging from their den. This episode highlights the true strength of the rulers of the ice kingdom as they raise their cubs in extreme conditions.