A mysterious call has reached the people of Etnord, with whom humanity and its allies fought a terrible war. Now the Etnord leave their worlds to face a mysterious goal. As we now know from a decoded radio message, the so-called Black Hole X is the target of the cosmic exodus. All this happens far away from the earthly sector on the other side of the galaxy, more than forty-three light years away in a space sector that can only be reached by wormhole passage. Two spaceships of the Space Army Corps of the Human Worlds have set out there to unravel the mystery: The STERNENKRIEGER and the SONNENWIND. Meanwhile, the wormhole connecting that distant region of the Galaxy with the earthly sector seems to become unstable. The astronauts still don't know it in the distance, but it is questionable whether a return from their expedition is possible at all... But two scientists are not impressed by such difficulties and dare the impossible.