Annie and her dog, Oscar, have had a busy day playing in the snow. Somehow Annie's red mitten has disappeared in all the fun. They look high and low. . . . It's not on the sledding hill, and it's not by the snow castles. Maybe an eagle carded it off to keep its baby's head warm. Or maybe a mouse is using it as a sleeping bag. When the sun goes down, Annie and Oscar have to give up their search …