The navy captain Avanti Planetaros is inspired by his astronomer-father to travel through outer space to reach other worlds. He becomes an aviator and, along with the young scientist Dr. Krafft, the driving force behind the construction of a space-ship. Despite oppostion from the mocking Professor Dubius, Planetaros gathers a crew of fearless men and takes off. During the long voyage, the crew becomes restless; a mutiny is narrowly avoided. Finally, they reach Mars and discover that the planet is inhabited by people who have reached a higher stage of development, free of diseases, sorrow, violence, sexual urges, and the fear of death. Avanti falls in love with Marya, daughter of the Prince of Wisdom, the head of the Martians. Marya shares his feelings and decides to return with him in order to bring the wisdom of the Martians to the backward Earthlings. (stumfilm.dk)