In the fairytale kingdom of Babenhausen, a young, self-appointed expert on love, Mr. Cazotte, is hired by the scheming Grand Duchess to help her secure an heir. While searching for a suitable future Princess, Mr Cazotte teaches the timid and introverted Crown Prince Lothar the art of seduction and lovemaking. But their plan soon backfires, when an heir is conceived out of wedlock and the royal family has to seek refuge in the castle of Rosenbad. Here, as rivals within the royal family close in on their scheme, Cazotte himself falls in love with Ehrengard, the maid of honor, and gradually learns that in fact, he's no expert on love at all.