The human race has advanced to the point that they are sending signals into space, hoping to get a response. They are just about to learn that their messages have been received. Two civilizations have heard humanitys shouts into the void. One, the Morians, are intent on destruction; theyve spent millennia traveling from galaxy to galaxy and obliterating anything in their way, leaving death in their wake. The other, the Hypertheans, are a peace-loving race who nevertheless realize that they must defend themselves and the rest of the galaxy from the Morians. They have formed the Federation of Galaxies, and one of their number has reached out to the people of Earth, offering to help them. Only time will tell whether humans will be able to work with the aliens and establish a protection force to keep the planet safe. If not, the end of the world might soon arrive. In this science fiction novel, humanity encounters two alien races summoned by their signalsone offering aid and one threatening doom.