As the car sped swiftly along, Gregg sat back with folded arms and gazed upwards at the now crystalline skies, wondering, as he had never wondered before, about that incomprehensible immensity which for centuries of successive generations man had silently respected. No authoritative voice had ever claimed to penetrate that supreme mystery. Priests had evoked the gods from that starry depth, poets had sung of the swinging hemispheres, scientists had traced comets and knew the quality of each solar earth; but still that vast arch spanned all the movements of crawling mankind, and closed him in like a basin placed over a colony of ants. True, it was an illusion, and man had always known that. For generations he had known that the universe contained more than his limited faculties could perceive. And beauty. There had always been the consoling fact of beauty, lulling the race of man to content, while every now and again a great mind arose and made one more effort to sweep aside the bejewelled splendour that hung between man and his final destiny--to know. And yet, a slight alteration in man's perceptive organs and that wide blue shell might shatter and disclose a thousand new forms, like fantastic cities shaped in the clouds at sunset. Physiologists claimed that the addition of a single lobe to the human brain might mean that man would know the future as well as the past. What if that miracle had been performed? By such means man might have come to know not only the future, but other dimensions as yet unnamed or merely sketched out by the mathematician in brief, arbitrary terms. Until that time came, man's deepest speculations about ultimate reality brought him no nearer to the truth than the child worrying himself to sleep over the problem of what happened before God made the universe. Man remained, in that sense, as innocent as a child, from birth to death. Until the actual structure of the cells in his brain suffered a change man could not actually know. Einstein could say that we were probably wrong in our basic conceptions. But could he say how we were to get right? The Clockwork man might be the beginning. And then, when that change had been wrought, that physical reconstruction, what else might follow in its train? The Truth at last, an end to all suffering and pain, a solution of the problems of civilisation, such as overpopulation and land distribution, the beginning of human sovereignty in the universe. But Gregg had the sense to admit to himself that his generalisation was no more than a faint aurora hovering around the rumoured dawn of the future. It was necessary, in the first place, to posit an imperfect thinking apparatus. After all, the Clockwork man was still a mystery to be solved, and even if he failed to justify a single theory born of merely human conjecture, there still remained the exhilarating task of finding out what actually he was and how he had come to earth. III