When Prince Aldo Morosini, an expert in ancient stones, met Simon Aronov, nicknamed the Lame Man of Warsaw, he did not expect the mission that this mysterious character would entrust to him: to find the four missing stones from the pectoral of the High Priest of the Temple of Jerusalem, a gold plaque in which twelve precious stones were set. According to tradition, Israel would regain its ancestral homeland when the reconstructed pectoral could return there... After discovering the first three of these stones, "The Blue Star", "The Rose of York" and "The Opal of Sissi", Morosini left for Spain, invited by King Alfonso XIII. It was during a party in Seville that the antiquarian prince noticed, on a portrait of Queen Joanna, who was called the Mad One, a jewel that could be the one he was looking for. From Seville to Prague, then to Zurich, Aldo Morosini, aided by his archaeologist friend Adalbert Vidal Pellicorne, will hunt down the stone that is the most evil and bloodiest of all. But, on his way, he will have to face the danger posed by Anielka, the woman imposed on him and her shady family. In this fourth and final volume of the saga of the Lame Man of Warsaw, Juliette Benzoni takes us on adventures full of twists and turns and suspense where love and money kill.