A housekeeping and mother-craft expert named Mrs. Fillyjonk moves in next door to the Moomins. Seeing the state of the Moomin house, she takes action, shaming them into hiring a maid. When Misabel the maid arrives, it's immediately clear she needs a little cheering up, and since Mrs. Fillyjonk has mysteriously disappeared, the Moomins set about teaching her how to enjoy life.