It's 1865 in the Bismarck-threatened principality of Valdastein, and handsome King Maximilian--though happy in his carefree, mistress-y bachelorhood--reluctantly agrees with his ministers that it's time to produce an heir. So off goes King Max to the Grand Duchy of Aldross, where Princess Sophie is the elder, marriageable daughter. But her sister Princess Zita is prettier--and spunkier: afraid that she'll miss seeing King Max, Zita disguises herself as a peasant waitress and serves the King at a roadside inn before he reaches the castle. Sure enough, it's mutual love almost at first sight, though Max is bewildered by this peasant's tri-lingual elegance. And he courts the mysterious Zita avidly: ""I can feel you vibrating to me as I am vibrating to you."" Zita, of course, is confused--especially when Max, not knowing her royal secret, seems to be suggesting a little mistreSs action. She flees from him; he finds her, discovering that she's a marriageable princess. But Zita turns down Max's proposal, afraid that he (like other royal husbands) will fool around with courtesans on the side. So Max will have to invade Zita's bedroom, threaten her with rape (sort of), and make a no-mistress vow. . . before the happy ""Paradise of Love"" ending. Sheer operetta--without the music--but easier to take than some of the more pseudo-serious Cartlands.