The Missing Mitten Mystery by Steven Kellogg

nnie 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 carried 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 and go inside. But when Annie looks out the window, something red catches her eye. . . .