Fishmonger Polina is sleeping badly because she’s worried about her brother. A tea given to her by a strange old woman transforms her sleep into a fairy tale. In a sort of underworld, she takes part in a competition that aims to determine whether or not she has what it takes to become a Tzarevna, or tsar’s daughter. The Tzarevna is an archetypical figure in Russia’s folklore and world of fairy tales. And the film is itself a fairy tale, in which Polina has to pass various tests in order to return at the end as a different person.