April 1902 Retired detective of the St. Petersburg police Rodion Vanzarov was asked to return to duty - a matter so complex that only he could do it. And on the very first day of the investigation, Vanzarov... kills the crime victim! Or was the victim already dead before?.. The police of the city of Pavlovsk, where a dead-alive girl was wandering the streets, could not answer this question. The great criminologist Lebedev was unable to solve the mystery of what happened: something important kept slipping out of sight. And this continued until Vanzarov heeded the warning of a mysterious bibliographer named Trupp...