The Visitors who belonged with an entirely different phylogeny, the highly developed race of some system of evolution from the infinitely distant past, became aware of signs of the rarest phenomenon in the Universe - Intelligence. During a period of several centuries, the involvement of Visitors was in the role of invisible observers. They did not intervene, or become involved with subjects of their study. But when the course of Planet Earth turned towards the catastrophe, they decided to step in, and help save at least some members of the human race.