A prince is in River Heights. A prince! This is big news. A prince from a relatively minor royal Italian family has come to River Heights to deliver a painting to Mrs. Mahoney, a friend of the royal family. Everyone excited about the royal visit--so you can imagine how shocking it is when the prince is thrown into jail. His family thinks he stole the painting! Nancy and her dad have reason to believe that the prince is innoncent. But can they prove that to everyone else?