1981. Ivan Petrovich Cherkasov is investigating a complicated case. And, as always, the bosses are dissatisfied with them. He is reprimanded at meetings and meetings, threatened with retirement. It is quite difficult for Cherkasov to imagine himself retired. But he understands that he began to get tired quickly, to miss important information. In general, to grow old. Yes, there is also a young investigator who knows how to work on the computers that have appeared, and also brings a lie detector to the department. Ivan Petrovich decides to give in. But in the last case, he must put an end to it himself.