The series is based on a novel narrated by Sergei Samarin. A demonic nobleman and a Moscow detective begin investigating the murders of those who had reported on the Decembrists. The novel offers an original plot, an unexpected ending, vivid characters, and a dark atmosphere of mystical Saint Petersburg. The author, Aleksandr Gonorovsky, is a nominee for the "The Big Book" and "Oscar" awards. The book was written in collaboration with Ilya Egarmyn and is based on real events, including the appearance of notes with poems by Alexander Pushkin near the victims.