Based on the bestselling children's book by Michael Rosen and Helen Oxenbury. the story follows siblings Stan, Katie, Rosie, Max, the baby, and Rufus the dog, who decide one day to go on an adventure through whirling snowstorms, oozing mud, and dark forests in search of bears. But when Rosie and Rufus become separated from the rest of the family, it looks like bear hunting might not be quite as fun after all.