Count Averin. The Sorcerer of the Russian Empire

The first book in the series about the investigations of Count Averin.

Magical St. Petersburg, 1982.
Count Averin investigates the murder of a nobleman's son, in which the divs, cruel magical beings from the Wasteland, are accused. They obey humans but go out of control at the scent of blood or the weakness of their master.
Averin realizes that this is not the first murder and that a very powerful div is behind the crimes. At the same time, a huge demonic cat appears in Petrograd...