Year 1333. Mysterious things happen in the capital of the Golden Horde. At an inn, a guest disappeared from a room locked from the inside. Where did the foreigner come from, calling himself an arrival from the land of the setting sun? Who is involved in his mysterious disappearance: sorcerers from secret dwellings in the Mordovian forests, Bulgar merchants, or papal envoys? Why is his fate a concern to the very favorite wife of Khan Uzbek—powerful and treacherous Taidu-la? Handling all of this has been assigned to the assistant of the emir of Sarai. He doesn’t yet know how far the trail will lead him.