The male growled again, his lips wrinkling back in a snarl as the emanations of fear from the men he could not see reached panic peak. He still crouched, belly flat, on the protecting pads of his cage; but he strove now to wriggle closer to the door, just as his mate made the same effort.

Between the animals and those in the control cabin lay the others....forty of them. Their bodies were cushioned and protected with every ingenious device known to those who had placed them there so many weeks earlier. Their minds were free of the ship, roving into places where men had not trod before, a territory potentially more dangerous than any solid earth could ever be.

Operation Retrograde had returned men bodily into the past, sending agents to hunt mammoths, follow the roads of the Bronze Age traders, ride with Attila and Genghis Khan, pull bows among the archers of ancient Egypt. But Redax returned men in mind to the paths of their ancestors, or this was the theory. And those who slept here and now in their narrow boxes, lay under its government, while the men who had arbitrarily set them so could only assume they were actually reliving the lives of Apache nomads in the wide southwestern wastes of the late eighteenth and early nineteenth centuries.

Above, the pilot's hand pushed out again, fighting the pressure to reach one particular button. That, too, had been a last-minute addition, an experiment which had only had partial testing. To use it was the final move he could make, and he was already half convinced of its uselessness.

With no faith and only a very wan hope, he sent that round of metal flush with the board. What followed no one ever lived to explain.

On the planet the installation which tracked the missiles flashed on a screen bright enough to blind momentarily the duty man on watch, and its tracker was shaken off course. When it jiggled back into line it was no longer the efficient eye-in-the-sky it had been, though its tenders were not to realize that for an important minute or two.

While the ship, now out of control, sped in dizzy whirls toward Topaz, engines fought blindly to stabilize, to re-establish their functions. Some succeeded, some wobbled in and out of the danger zone, two failed. And in the control cabin three dead men spun in prisoning seats.

Dr. James Ruthven, blood bubbling from his lips with every shallow breath he could draw, fought the stealthy tide of blackness which crept up his brain, his stubborn will holding to rags of consciousness, refusing to acknowledge the pain of his fatally injured body.

The orbiting ship was on an erratic path. Slowly the machines were correcting, relays clicking, striving to bring it to a landing under auto-pilot. All the ingenuity built into a mechanical brain was now centered in landing the globe.

It was not a good landing, in fact a very bad one, for the sphere touched a mountain side, scraped down rocks, shearing away a portion of its outer bulk. But the mountain barrier was now between it and the base from which the missiles had been launched, and the crash had not been recorded on that tracking instrument. So far as the watchers several hundred miles away knew, the warden in the sky had performed as promised. Their first line of defense had proven satisfactory, and there had been no unauthorized landing on Topaz.