Contemporary Moscow. While riding her bicycle one day, Alyona, a shy librarian, accidentally collides with Liza, a dazzling blonde. When she wakes up in the hospital, she discovers that she and Liza have exchanged bodies.
Marine scientist Fred Miller designs the world's first underwater home, but when the business magnate funding his work threatens to end the project, Miller volunteers to live in it with his own family to prove it's practi
