The advance of science along wide frontiers of knowledge has been so rapid during the last few decades that we no longer find it remarkable. Yesterday's miracles are today's commonplace. Scientific discoveries have not only kept pace with science fiction, in several spheres truth has proved stranger than fiction.

The alliance between medicine and electronics has provided ample example. When bio-chemistry completes this formidable triumvirate unlimited scope opens for the human body. The pioneer work of the Twentieth Century had opened up new vistas by the dawn of the Twenty-fifth. Like all new knowledge it was neutral in itself, but its potential, for good or evil, was staggering. A strange new race of modified men had fantastic powers and a kind of immortality. But something... the human touch itself... had been lost, and in consquence a terrible barrier grew between the New Race and the old. It looked as if a cataclysmic war would be inevitable....

The planet had endured an annihilating cosmic nuclear cataclysm. To all intents and purposes humanoid life had apparently ceased to exist.

However, there were those who had seen the conflict coming, and who had taken steps accordingly. Man in his natural state would not have been able to survive, but Hengist and MacIlraith, working desperately against time had produced something different, something that was human in many respects, but which they hoped would be able to survive in an atomic aftermath. Like the phoenix rising from the ashes, the Sons of Tomorrow triumphed over a deadly, hostile environment. But the aliens who had started the war returned intent on claiming the planet they thought was dead.

Could a tiny handful of strangely changed human beings succeed in surviving against such incredible odds? Could they do more than survive? Could they strike back in the name of massacred humanity?.