A series of murders took place in the city of Votkinsk on the eve of the Tsarevich Alexander’s visit during his trip through the Russian Empire. The governess of the family of the head of the Votkinsk ironworks, Tchaikovsky’s Frenchwoman Fanny Durback, joins the investigation led by the secret adviser Lagunov. Together they go through trials and come face-to-face with shapeshifting officials. They will have to find the true criminal.
In the second part, Kazan detective Lagunov is sent to Izhevsk, where he meets again the charming Frenchwoman Fanny Durback, who has entered the service in the house of Commander Neratov of the Izhevsk оружейного завод. The adviser must find the kidnapper of secret drawings and solve a murder. And Fanny, as usual, helps the detective in his search—while getting herself into trouble. Feelings flare between them. But what is it—love or a chance connection?