Damia and Afra Raven-Lyon had reared their children in a brilliant and unorthodox way. All their young had been 'paired' when six months old with the furry, one-eyed Mrdinis, the only other sentient beings in the Alliance, who could communicate with humans by their 'dream messages'. Together, Man and Mrdini worked to create prosperous worlds and guard against the terrible threat of the annihilating Hivers. And now, in the deeps of Space, Mrdini scouts had crossed the path of three Hive ships - ships that were giant hu1ks of cell units bearing the queens and workers out into space, to breed and multiply and destroy wherever they found a viable planet. It was the four elder children of Damia - Laria, Thian, Rojer and Zara - all uniquely talented in their various ways, who were to play their part, helped by their life-long Dini friends, in the conquering and investigation ot the Alien threat of the Hivers.