Outside more of the green beams were concentrating on this one point of resistance. More--more-- The violet beam spread across the canopy of blackness, supporting it against the pressing, driving rays of pale green. Then the gathering fleet was driven off, just as it seemed that that hopeless, futile curtain must break, and admit a flood of destroying rays. Great ray projectors on the ground drove their terrible energies through the enemy curtains of blankness, as light illumines and disperses darkness. And then, when the fleet retired, on all Earth, the only life was under that dark shroud! * * * "We are alone, Trest," said Roal, "alone, now, in all the system, save for these, the children of men, the machines. Pity that men would not spread to other planets," he said softly. "Why should they? Earth was the planet for which they were best fitted." "We are alive--but is it worth it? Man is gone now, never to return. Life, too, for that matter," answered Trest. "Perhaps it was ordained; perhaps that was the right way. Man has always been a parasite; always he had to live on the works of others. First, he ate of the energy, which plants had stored, then of the artificial foods his machines made for him. Man was always a makeshift; his life was always subject to disease and to permanent death. He was forever useless if he was but slightly injured; if but one part were destroyed. "Perhaps, this is--a last evolution. Machines--man was the product of life, the best product of life, but he was afflicted with life's infirmities. Man built the machine--and evolution had probably reached the final stage. But truly, it has not, for the machine can evolve, change far more swiftly than life. The machine of the last evolution is far ahead, far from us still. It is the machine that is not of iron and beryllium and crystal, but of pure, living force. "Life, chemical life, could be self-maintaining. It is a complete unit in itself and could commence of itself. Chemicals might mix accidentally, but the complex mechanism of a machine, capable of continuing and making a duplicate of itself, as is F-2 here--that could not happen by chance. "So life began, and became intelligent, and built the machine which nature could not fashion by her Controls of Chance, and this day Life has done its duty, and now Nature, economically, has removed the parasite that would hold back the machines and divert their energies. "Man is gone, and it is better, Trest," said Roal, dreaming again. "And I think we had best go soon." "We, your heirs, have fought hard, and with all our powers to aid you, Last of Men, and we fought to save your race. We have failed, and as you truly say, Man and Life have this day and forever gone from this system.