The early twenties of the 20th century, Petrograd. Time of troubles: regime's paralysis, chaos, rampant crime. Boris Letush is investigating the murder of his brother, a well-known lawyer. Experienced robber, Lyonka Panteleev - is under suspicion - he was arrested and imprisoned in a remand prison. Only few people know that Panteleev, a former security officer, is a secret agent of the criminal investigation department. "If the subject of the killer agent comes up at the trial, it will be a failure!" - says the head of the criminal investigation, Matveev. He insists on the immediate liquidation of Panteleev, suggesting to act out the suicide in jail. Letush is against lawlessness: one should always prove the suspect's guilt first. "Justice is not the right to judge, but the right court, a fair one!" - he says. The conflict is resolved unexpectedly: Panteleev escapes from the prison. Who organized the escape and why? What was his goal?