When a mysterious and dangerous whirlpool phenomenon appears in the tropics of the Atlantic Ocean, Belka and Strelka, the first astronauts on their way back from a mission to Saturn, are sent to investigate. As they venture down into the swirling ocean depths, they discover a mysterious UFO attempting to steal all of Earth's water. With the help of their good friends, Belka and Strelka once again perform a heroic mission to save both our planet and the distant home of their new alien friends.