Having seen a depressed Polar Bear in the zoo, Grandfather and Roo set off on an expedition to see if they can find the last Polar Bears. The journey is dangerous as they travel on HMS Unsinkable to Walrus Bay. The fun really starts as they survive a 3-day snowstorm, local wolves, Roo's mood swings and more. Conditions are appalling and the wind is fierce, especially when it blows away all the supplies, but Grandfather and Roo have the staying power to survive all this and see the last Polar Bears.