Huge, glistening, streamlined metal monsters. They shot from the dark opening. A line of twenty, they glowed with a deadly field of gamma radiation and death-spray. And Cadmus kept running away from them. His heart pounded with a deathly fear and awe as he hurled himself down the steep trail. He glanced back a few times. That was enough. Those great metal tanks were deadly to any living thing near them. They sped from the cavern, headed in a grim straight line directly for the Machine. Once set as his father had set their automatic robot controls long ago, nothing could divert them from their objective. Straight down the slope they plunged in silent, ferocious intent. Cadmus remembered other things now. Of how his father had installed secretly a transmat sender in a Terran museum where such curious mementos as giant robot tanks were no longer of interest to Terrans. One by one, via transmat, the tanks had been transported to this hidden cavern on the edge of the valley. In that last ghastly war, robot tanks and drone planes had been employed almost entirely in place of human beings. Atomic engines were built and used to drive these drone planes, tanks, ships. But no living thing could pilot them, nor come within a quarter of a mile of them, and survive. They were robot controlled. Man's final contribution to annihilative warfare. Equipped with raw, unshielded atomic engines, the tanks were deadly beyond imagination, with atomic bombs as warheads, and giving off a sheet of robot death-spray. They were impervious to any kind of atomic weapons for they were the ultimate in robot-controlled atomic weapons. Silent, implacable, they rushed down the slope, over rock and through brush, and finally over mounds of dead and dying. The human lemmings rushing to their death didn't notice the tanks. They did not notice anything. Up and up over mounds of clawing bodies and hills of dead the terrible robot weapons climbed. Over heaps of human lemmings, red and yellow and black Terrans, and yellow Martians. And then they struck the smooth gleaming side of the Machine. The machine exploded! The valley was suddenly a seething boiling cloud of chaos. Bits of Gray God rained for miles over the desert, mountains and ruins of Akal-jor. Boiling dust clouds rose blackly, flung by a tremendous flash like a ball of fire the size of the setting sun. Churning debris climbed thousands of feet in the air, while smoke climbed higher. The dying day was relighted by a searing light, golden, purple, violet, gray and blue. Then came the first of a series of air-blasts, to be followed almost immediately by the sustained and awesome roar.