On a little island in a lake, three children and their mother live in a cottage shaped like a hat. One day, their mother went to the mainland to find yarn to make new clothes for the children. While she is away, the children try to help around the house, but housework is much harder than they had thought.
They have lots of fun sweeping the chimney—but they get very dirty. They wash their clothes in the lake and dry them over a fire—but fires are hard to control... Will Hat Cottage still be standing when their mother returns?