Two residents of the small town of Pridonsk in the Rostov region - a restaurant owner and a nuclear power plant engineer - independently contact the Gloria detective agency. One of them’s wife disappeared, the other’s father, a deputy of the local council, was killed. The city is allegedly rampant by the mafia, which has bought everything and everyone. Gloria director Denis Gryaznov checks these facts and does not take them seriously until his employees become random victims of the Don mafia.