He felt a sort of hysterical composure. He opened the chest. It was patently artificial. There were such details on the inside as would be imagined in a container needed to fit something snugly. At the edges of the opening there were fastenings like the teeth of a zipper, but somehow different. Coburn knew that when this was fastened there would be no visible seam. Whatever wore this suit-that-looked-like-Dillon could feel perfectly confident of passing for Dillon, clothed or otherwise. It could pass without any question for-- Coburn gagged. _It could pass without question for a human being._ Obviously, whatever was wearing this foam-rubber replica of Dillon was not human! Coburn went back to where he had to climb down the cliffside again. He moved like a sleep-walker. He descended the fifty-foot cliff by the crevices and the single protruding rock-point that had helped him get up. It was much easier going down. In his state of mind it was also more dangerous. He moved in a sort of robot-like composure. He moved toward the girl, trying to make words come out of his throat, when a small rock came clattering down the cliff. He looked up. Dillon was in the act of swinging to the first part of the descent. He came down, very confident and assured. He had two camera-cases slung from his shoulders. Coburn stared at him, utterly unable to believe what he'd seen ten minutes before. Dillon reached solid ground and turned. He smiled wryly. His shirt was buttoned. His tie was tied. "I hoped," he said ruefully to Janice Ames, "that the Bulgars would toddle off. But they left a guard in the village. We can't hope to take an easier trail. We'll have to go back the way you came. We'll get you safe to Salonika, though." The girl smiled, uneasily but gratefully. "And," added Dillon, "we'd better get started." He gallantly helped the girl remount her donkey. At the sight, Coburn was shaken out of his numbness. He moved fiercely to intervene. But Janice settled herself in the saddle and Dillon confidently led the way. Coburn grimly walked beside her as she rode. He was convinced that he wouldn't leave her side while Dillon was around. But even as he knew that desperate certitude, he was filled with confusion and a panicky uncertainty. When they'd traveled about half a mile, another frightening thought occurred to Coburn. Perhaps Dillon--passing for human--wasn't alone. Perhaps there were thousands like him. Invaders! Usurpers, pretending to be men. Invaders, obviously, from space! II They made eight miles. At least one mile of that, added together, was climbing straight up. Another mile was straight down. The rest was boulder-strewn, twisting, donkey-wide, slanting, slippery stone. But there was no sign of anyone but themselves. The sky remained undisturbed. No planes. They saw no sign of the raiding force from across the border, and they heard no gunfire.