A beautiful maiden, Marya Morevna, gives her prospective husband, the mighty warrior Nikita Kozhemyaka, three riddles to solve before she'll marry him. Before he can tell her the answers, the Russian land is invaded by the armies of Kashchey the Immortal, in whose footsteps death and destruction follow. Marya is abducted by Kashchey, and Nikita finds his home in ashes. Nikita meets a kindly wizard who gives him a cap of darkness. With it, the hero will find a way to save his bride and rout Kashchey.

The film is based on Russian folk tales. After serving in the army, a soldier is returning home. In an enchanted forest he meets Ivanushka whose mother, Maria the Wonderful Weaver, has been stolen by the evil, treacherous and elusive Tsar Vodokrut XIII. The brave soldier decides to help Ivanushka. In search of the boy’s mother, he will traverse with him the enchanted forest and will go down to the sea bottom.
A Fantastic and Magical Story of a Fairyland Kingdom Under the Sea. An old soldier helps a young boy find his mother, who's been kidnapped to the magical underwater kingdom in a remote Russian lake.