Seventh-grader Sasha Menshikov is finishing the school year at a new school and lives with his aunt Nina in a small picturesque town. Sasha's mother, a famous scientist, brought him here from Moscow for the duration of her next expedition. Things didn't work out with Sasha's classmates; after school, he often walks alone in nature. One day in the forest, Sasha finds a little fox caught in a trap. Having learned that poachers are hunting for the fox cub, the boy hides him in a dugout deep in the forest and begins to nurse him. This begins a touching and adventurous story about friendship, responsibility and justice.