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.

• Lenfilm
• Goskino USSR
• Vladimir Korenev
• Anastasiya Vertinskaya
• Mikhail Kozakov
• Anatoliy Smiranin
• Nikolai Simonov
• Vladlen Davydov
• Yuri Medvedev
• Aleksandr Zakharov