Middle of the 16th century. The times of Ivan the Terrible and the oprichnina. The Tsar's servant Yuri Volkov travels to Suzdal to investigate a long-standing case related to Solomonia Saburova. Once upon a time, Grozny’s father was married to her, but he divorced because she turned out to be barren, and married Elena Glinskaya. In general, the story is really old, forgotten, overgrown with the past. Why is John interested in her? And what does it matter to the Tsar that the Volkovs are distant descendants of the Polotsk prince Vseslav Bryachislavich, who seemed to know how to transform into a wolf? And the solution is simple: John believes that the wolf will find what the sovereign’s dogs could not find - he will find traces of one baby prince, who has been missing for a long time. This boy was given birth to by Solomonia, who was already divorced and tonsured a nun—she gave birth and hid it.