Unaware that it is a part of the natural growth process, Shelly is frightened when her tooth falls for the first time. Moreover, nanny, in a moment of anger, says that she will soon lose all her teeth due to her constant blabbering, thereby, adding to her fears. She is finally put at ease when her father tells her of the tooth fairy who will replace her old tooth with a stronger one. But trouble brews, when the news of Shelly's doubt in the existence of a tooth fairy reaches the evil professor's ears.