In the fourth millennium, the Sun burned the Earth. Earth's civilization has perished. But scientists predicted the catastrophe long ago, and seeding ships with earthling embryos, robots and a database of earthly culture were sent from Earth. One of these ships found Thalassa - a beautiful world. Years have passed, and Thalassa has its own civilization, which remembers its lost homeland. And then, one day, a spaceship appeared in the sky of the planet, the people from which declared that they had arrived from a long-lost Earth.