Germany, 1830. Wolfgang Gottlieb (he prefers the German form of his name) Mozart is getting on in years, but is still remarkably spry for his age. And things are looking up when he is asked to give piano lessons to the young Princess Victoria. He is less sure of his good fortune, however, when the princess, during her first lesson, makes a most unusual demand of him. And things go from bad to dangerous when she becomes heir apparent to the throne and seems destined to be the victim of a tug-of-love between the new king, William IV, and her unwise mother, the Dutchess of Kent. When the king's brood of illegitimate children, the FitzClarences, join in, the situation rapidly gets alarming overtones, and when one of the guests at a Windsor Castle reception finds that drinking out of other people's glasses can have fatal consequences, Mr. Mozart has to face up to the fact that someone may have designs on his rather enchanting new pupil.