People living at a seashore town are frightened by reports of an unknown creature called "the sea devil". Nobody knows what it is, but it's really the son of doctor Salvator. The doctor performed surgery on his son and now young Ichtiander can live under water. This gives him certain advantages, but also creates a lot of problems.
Timofey Suvernev comes to Moscow from a distant island to study. Tim successfully passes the exams at the institute, and immediately plunges into a turbulent student life. Through hard work and study, he achieves brilliant success, his student work, which he wrote together with his classmate Galtsov, receives a gold medal at the competition.
General Zhuravlev fought on the fronts of World War II, and is now designing spacecraft. Sending a rocket with astronaut Borodin on the flight, he recalls the namesake of the astronaut - a young tankman whom he had the chance to meet on the roads of war ...
