In a Scottish castle bought by a Russian oligarch, on the night before Christmas, a beautiful photo model was murdered. The police immediately arrested her boyfriend, because all the evidence pointed to him: the guy had quarreled with the victim, and fingerprints of his were found on the pistol. Yet each of the guests had a perfect alibi—100%. Still, the suspect kept insisting he was innocent. The police didn’t believe him, but Drongo—an expert analyst—was able to convince him. And the expert decided to thoroughly look into the oligarch’s family relationships…