Colonel Mikhail Avdeev is the chief of police of the Port city, known for his decisive methods in the fight against crime. By doing this, he hinders the dreams of lawyer Medushevsky — to become the shadow master of the city. Avdeev personally organizes an operation to detain drug couriers working for Medushevsky, but a police convoy on the way back is shot by people in clown costumes. All the law enforcement officers are killed, and the criminals escape from the riot police car. The doctors who arrived at the scene discover that Avdeev has survived, but the colonel is in no hurry to rejoice, because the death of the fighters is on his conscience.…

Avdeev begins to dig into Medushevsky and finds out that there is compromising evidence against the lawyer in the St. Petersburg archive: a few years ago, a murder case against an assistant prosecutor thundered across the country. Then Medushevsky took over the business of former crime bosses. Avdeev meets Andrey Vershinin, his friend from the orphanage, in the archive and steals a secret case. The policeman does not have time to study it: on the way to the port, he gets into a fatal accident. Andrey Vershinin from the archive is unexpectedly appointed chief of police in Portovo.

Lieutenant Colonel Vershinin arrives at the Port, gets acquainted with his deputy Knyazev and tries to understand current affairs on the spot, but is confronted with the disdainful attitude of colleagues and subordinates. He goes to Avdeev's house hoping to find information there that will shed light on the circumstances of his friend's death, and meets journalist Anna Loginova there. She notes that there are some things missing in the house. Their conversation is interrupted by a vigilant police squad…