One of the digging machines was brought into play and they labored to get the prisoned man free, but as they cleared the broken stone and rubble from around his face, it became evident that the effort was useless. The eyes were glazed, the head hung limp. Adam stepped back against the wall of the cave-in around them, and as he did so his hand touched it. Once more he noticed it was both smooth and warm. He turned, and in the light of the atomic lamps now blazing across the top of the cave-in examined it. It was not only smooth and warm, but polished; and just over his head he could see where the rock stopped and metal began--a clean-fitted job, a manufactured wall! "Jake!" he called excitedly, "bring that digging machine over here for a second. The one with the cutting head." The little engineer turned, and bounded over in a couple of steps, digging machine in hand. "Why, that's a metal wall," he cried, and applied the head for a moment in a brief surge of power. The bit cut out an inch-deep circle of metal, dropping it on some of the rubble with a tinny clang. Jake bent to pick it up. "It's light enough to be beryllium," he said, handing the disc to Adam, and turning back to the wall, drove his cutter into it with renewed energy. "What are you doing?" demanded the mate, hefting the disc of metal. "This wall sounds hollow. Here goes!" He had driven the machine deep in, and stepping back, pulled the handle marked "Split." There was a sudden rending clang; a crash and a six-foot section of the wall fell inwards. The two men stared into the hole it had left, heedless of the fact that the other members of the excavating crew were crowding up behind them. They were looking into a low square room, perhaps twenty feet across. At the far side was a doorway, and in the doorway stood a man! To be sure he was such a man as none of them had ever before seen. He was not over four and a half feet tall, yet with arms as long as an earthling's hanging down below his knees, tremendously broad shoulders, and a head that seemed permanently pushed forward and downward above them. Below that head the creature was wrapped from neck to toe in some shimmering blue material with a metallic luster, banded around the arms and legs with red metal. As they gazed in astonishment, the man took two steps forward, his head bobbing on his neck at each step, opened his lips, and uttered "Wahwahroo!" in a voice thick with gutturals. * * * * * Adam glanced around at his own men, then once more at the Plutonian dwarf, whose face, as far as he could judge, bore an expression of intense interest rather than of fear or anger. The remark, he judged, would be a greeting. "Wahwahroo!" he replied amiably, but the Plutonian continued to stare in a manner that indicated Adam's first lesson in this unknown tongue was far from a success.