A new teacher and her brother, who has been appointed head of fisheries control, arrive in a village on the shores of an estuary. Despite the hidden resistance of their fellow villagers, they manage to engage the village schoolchildren in an active fight against poachers.

Senior Lieutenant Vasily Bodrug and his wife Evgenia arrive at the border outpost after the wedding to serve. An intruder was killed while trying to cross the state border, and border guard Vaskov was injured during detention. Vasily, risking his life, detains an accomplice of the violator. But a complete surprise for the lieutenant was the arrival of his former lover Vyacheslav to his wife.

The mining town of Donetsk with specifically difficult mining and geological conditions. To the new chief engineer Marat Zhukov, the mine directorate sets the task to close the dangerous lava, where the Dotsenko team works - one of the best mines has ceased to fulfill the plan. Having made the calculations, Marat discovered the possibility of reaching the normal layer and he was able to convince the authorities that it was not necessary to disband a friendly team.