"You came to spy under the cover of a barbarian trader," smoothly, without pause, the man changed language in mid-sentence, slipping from the Beaker speech into English. But long experience in meeting the dangerous with an expression of complete lack of comprehension was Ross's weapon now. He stared somewhat stupidly at his interrogator with that bewildered, boyish look he had so long cultivated to bemuse enemies in his past. Whether he could have held out long against the other's skill--for Ross possessed no illusions concerning the type of examiner he now faced--he was never to know. Perhaps the drastic interruption that occurred the next moment saved for Ross a measure of self-esteem. There was a distant boom, hollow and thunderous. Underneath and around them the floor, walls, and ceiling of the room moved as if they had been pried from their setting of ice and were being rolled about by the exploring thumb and forefinger of some impatient giant. CHAPTER 13 Ross swayed against a guard, was fended off, and bounced against the wall as the man shouted words Ross could not understand. A determined roar from the leader brought a semblance of order, but it was plain that they had not been expecting this. Ross was hustled out of the room back to his cell. His guards were opening the cell door when a second shock was felt and he was thrust into safekeeping with no ceremony. He half crouched against the questionable security of the wall, waiting through two more twisting earth waves, both of which were accompanied or preceded by dull sounds. Bombing! That last wrench was really bad. Ross found himself lying on the floor, feeling tremors rippling along the earth. His stomach knotted convulsively with a fear unlike any he had known before. It was as if the very security of the world had been jerked from under him. But that last explosion--if it was an explosion--appeared to be the end. Ross sat up gingerly after several long moments during which no more shocks moved the floor and walls. A line of light marked the door, showing cracks where none had previously existed. Ross, not yet ready to try standing erect, was heading toward it on his hands and knees when a sharp noise behind him brought him to a stop. There was no light to see by, but he was certain that the scrape of metal against metal sounded from the far side of the wall. He crawled back and put his ear to the surface. Now he heard not only that scraping, but an undercurrent of clicks, chippings.... Under his exploring hands the surface remained as smooth as ever, however. Then suddenly, perhaps a foot from his head, there sounded a rip of metal. The wall was being holed from the other side! Ross caught a flicker of very weak light, and moving in it was the point of a tool pulling at the smooth surface of the wall. It broke away with a brittle sound, and a hand holding a light reached through the aperture.