Vladimir Korenev, Anastasiya Vertinskaya, Nikolay Kuzmin, Mikhail Kozakov, Anatoly Smiranin, Nikolay Simonov, Vladlen Davydov, Valery Kudryashov, Albert Antonyan, Mikhail Medvedev
People living at the seashore town are frightened by reports about the unknown creature called "the sea devil." Nobody knows what it is, but it's really a son of a doctor Salvator. The doctor performed a surgery on his son and now young Ihtiandre can live under water. This gives him certain advantages, but creates a lot of problems.