The legendary investigator of the FES, Major Nikolai Kruglov, leaves the service and returns to his hometown, where he is going to quietly meet old age. Kruglov hides from his friends that his resignation was a forced measure: as a result of his mistake, an inexperienced operative ended up in a coma. 

The idyll prevailing in his small homeland turns out to be deceptive, and Kruglov himself quickly turns from a well-deserved pensioner into a dangerous fugitive and hostage-taker. 

The investigation begins with local young police officers: two twin brothers — operative Stas and investigator Andrei, as well as criminologist Aglaya. With the help of Maisky and Rogozina, Kruglov uncovers the gang and frees the hostages. 

Kruglov is invited to give a course of lectures at the University of the Ministry of Internal Affairs, where his students are "new cops" — Stas Shcherbakov, Danila Bestuzhev and Aglaya Titova. They have not only theory ahead of them, but also practice in solving crimes, in which they cannot do without Kruglov's wise advice.