The novel "Agent Lilyk" continues the adventures described in "Dekker's Villa". Now the events are taking place under the watchful eye of the NKVD. Night reporter Marko Krylovych, together with the former police commissioner, is once again on the hunt for a mysterious serial killer. Since all the victims are somehow connected to Mark, the Chekists release him from prison and use him as bait. A separate intrigue surrounds the disappearance of the archives of the Netherlands embassy, which captivates the attention of the Chekists, the underground, our hero, and ourselves