Lars is a young polar bear cub who, naïve of the ways of the world, befriends a young seal pup, much to the annoyance of the other bears. After finding a solution to the problems of predator and prey in the form of fish, Lars finds himself in a tropical rainforest and by the time he gets back home the fish are drying up and the bears are getting agitated. Since the local humans are having the same problem Lars assumes that something else is taking them: a black monster that is heading towards Lars' friends.