Many have come into contact with mysteries, but not everyone has the courage to solve them, especially if the solution involves mortal danger. Student Tikhon Zakolov is not one of them. Amazing adventures, paradoxical puzzles and unpredictable dangers await him on the way to his goal. Bravery and nobility, ingenuity and intelligence help the main character to unravel the mysterious incidents. Tikhon Zakolov and Nina Bragina's fellow travelers on the train are the thief Yesenin and the bandit Khambiev. And everything goes wrong. Events are developing rapidly. Accusations of murdering a cashier at a small station and two policemen at the station, fights on a moving train, hijacking a freight train, chases, a bank robbery, a duel on the territory of the ominous Giptilnik - these are just a small part of the tests that the main character has to go through to save the girl. But will it be possible to save her? After all, the main enemy is not yet known. And your own life is at stake. And if he loses, he can only choose his own death.