Marfa returns with her son to the Pacific island where she grew up and where her father worked as a lighthouse keeper. At the same time, her half-brother Ilya appears on the island, whom Marfa has not seen for many years. Marfa and Ilya are connected by a dark secret. But no matter how much they try to escape from the past, it overtakes them in the form of a mysterious whale cruising off the coast of the island and as if trying to convey something to Marfa.

Post-WWII Russia, industrial city of Sverdlovsk. Former opera singer and mother to four children, Nina Levitskaya knows nothing about the fate of her husband. Communist party functionary Alexander disappeared almost a year ago and is now rumored to be in Moscow. With life becoming increasingly hard for the family, Nina decides to risk it all in hope of a reunion. She hastily sells everything she can, gathers her children, and sets out for the capital.

Senior Lieutenant of the Navy Aleksey Alekhin, once descending to the seabed in a bathyscaphe, finds himself in a strange underwater cave that serves as a portal to a fabulous world. In this new unfamiliar place, he meets a little dragon left without a mother. Aleksey unwittingly becomes the dragon's guardian and friend and gives the baby the name Gorynych.

The boy doesn't remember his mother; she abandoned him and his father and moved to America. And the girl has no father. The children, behaving like adults, make the responsible decision to introduce their single parents and get them married.