Secrets of the Coastal Settlement

In the settlement by the Black Sea, where the heroes of the book Yurka, Kostya, Olga, and Dimka met and became friends, new vacationers appear — a father with his daughter Marina. Their behavior raises suspicion in Yurka, an expert on books and films about spies and secret agents.

The kids start to monitor the newcomers, unaware that this is the beginning of exciting adventures, during which they will not only uncover Marina's father's secret but also learn a lot about the history of intelligence from ancient times to the present day, about the lives of outstanding spies, and what qualities one needs to possess to succeed in such a difficult task.