A friendly group of children spends their summers in an old dacha village year after year. The kids have their own headquarters hidden from prying eyes in a corn field and a legend that says that a treasure trove of treasures of a princess who fled from Napoleon is hidden not far from the village. When a new girl Katya comes to the village with her mother, she becomes a bone of contention for best friends Sonya and Dasha. But it is not only friendship that will have to endure a test of strength. A certain businessman is going to buy a field with a hut and organize a construction market in its place. The children decide not to allow this to happen at any cost and after failed negotiations, they move on to active actions.

Andrey Romanov finds himself at the epicenter of a clash between Russian and Western intelligence services. Together with his team of top Russian special agents, he is recruited by GRU officer Maksim Kolosov for a special mission into enemy territory. The group's goal is to find out what is happening in a secret laboratory near the border of the country, where work is underway on a new biological weapon. Andrey also has a personal goal - revenge. The enemy's team is led by his father's killer. Andrey's group is completely secret; almost no one knows about its true purpose. Everything does not go according to plan when it becomes clear that there is a "mole" among them.

Fourteen-year-old Egor, having moved with his mother from St. Petersburg to Kaliningrad, begins a new life: another educational institution - the Kaliningrad Nakhimov School, new acquaintances, new friends, new circumstances and concerns... He immediately decides to gain authority and introduces himself as the brother of the legendary Nakhimov students Loginov. And the plan works at first - popularity allows him to become the star of the class.