October 1898. Petersburg has gone crazy: a lady is chewing a squirrel cap, a gentleman is crowing, jumping on the counter, a prison guard shot a prisoner. The suicide of an official of the Security Department is of particular concern: he drowned in the city center. Vanzarov is entrusted with a secret investigation: not only to catch the killer, but also to find the missing Machina Terroris - the Fear Machine. A mysterious invention may control actions, turning people into weak-willed somnambulists. To solve the mystery, Vanzarov must look into the darkest depths of hypnosis...