Clever and agreeably concise reworking of various folk tales, from the British playwright and children's author. Cinderella sets the stage. Mara (the fairy godmother) magically transforms the ragged serving-girl Amadea into a princess; a nearby rat who's curious about humans becomes Robert, a coachman. When midnight stikes, Robert becomes a rat again--but he retains human speech and thought. After a stint in a carnival sideshow, Robert is discovered by scientist Richter, who's impressed by Robert's abilities but skeptical of his supernatural explanations. So Robert settles down to live with another scientist, Jenkins; but then Jenkins' friend, Devlin the revolutionary, tricks Robert into betraying Amadea--the princess--and her husband. Incited by Devlin, a mob sacks the palace soon after Mara grants Robert human form. The prince is beheaded, Amadea burned as a witch. So Robert swears vengeance: having learned to play the recorder, he summons an army of rats to destroy Devlin--but even here matters don't proceed as planned. Well-handled but fairly obvious in intent; still, the approach is unusual.