The main character of the series "Diver" is Shurik, an enthusiast of underwater swimming. For his fearlessness and participation in risky swims, his friends have dubbed him the Black Macedonian. For many years, the guy has been living abroad, but one day his last Russian relative, his grandmother Pelageya Ivanovna, asks him to return to Kaliningrad. Shurik gladly agrees, as the police are currently chasing him for his involvement in black underwater archaeology. However, his problems do not leave him in Russia either. A killer emerges on the Baltic coast, hunting divers.