December, 1928. A former Moscow provincial prosecutor accused of espionage is being sought - the OGPU has discovered his connection with Austro-Hungarian intelligence. All the witnesses and accomplices have been interrogated and arrested, but there is no way to find him. And only a train ticket to Leningrad with a mysterious note with the time and place of meeting gives hope. Criminal investigation officers are sent to the carriage indicated in the note. They are accompanied by a professor at the Institute of Forensic Psychiatry, Grenich, in order to identify the spy's accomplice among the passengers...Yulia Lee and the Eksmo publishing house present a novel from the "Detective Retro" series - "Train to Leningrad", written based on the materials of the court report on the case of the anti-Soviet right-wing Trotskyist bloc . It tells about the mysterious and enigmatic events that took place in the early years of the young Soviet republic.