July 1885. Zagorsky and Gantzalin accompany a secret adviser S, traveling to the Far East on a diplomatic mission. On the way they stop briefly in Nizhny Novgorod, where a major annual fair is taking place.
Here Zagorsky meets a gendarmerie officer, Nikolai Nazarov, with whom they studied together in the cadet corps. Nazarov keeps watch on the revolutionary Zabelin, hoping to expose a terrorist cell. But on the day of Nazarov’s meeting with Zagorsky, the revolutionary is killed. Judging by the chervonets found on the dead man, he had been distributing counterfeit money tickets. Everything suggests that the alleged killer arrived from the Zheltuginsky Republic or from the Amur California. Zagorsky and Gantzalin go to a mine to investigate the circumstances of the murder and the production of counterfeit chervonets.