"A phoenix," replied Harg, "of the late Stone Age. A most curious creature; half animal, half bird. Originally it was a native of the planet Mars. It adapted itself to utter cold and airlessness when that planet's atmosphere waned. A few phoenix migrated to Earth, but failed to survive in our heavy atmosphere." "That explains," cried Sandra, "the legend of the phoenix prevalent in our day. It was believed that the bird destroyed itself in fire to rise again, reborn." "An amusing misapprehension," nodded Harg. "No doubt it was founded on someone's having seen a phoenix pass unscathed through flame. The creature was quite immune to temperature changes. But not to disease. It was this that, finally, caused its extinction. "Now, in this next chamber--" He paused, obviously piqued. "I must confess, we have been unable to classify this beast. It is utterly unknown to our science. Apparently it does not breed true, nor can we determine its age--" Larry and Sandra stared once at the quadruped in the booth, then broke into a duet of long and hearty laughter. Harg stared at them annoyedly. "Well?" he snapped. "Well?" Larry said solemnly, "Harg, you've caught a rare beast there. There are none left in your day and age except the two-legged variety." Harg said, "You know it, then? Its name, quickly!" "We call it," Larry told him, grinning, "the jackass!" * * * * * The tour of inspection completed, Harg returned his two captives to the cell they shared. When the door closed behind him, Larry turned swiftly to Sandra. "Now what? I'm not sure I understand just what's going on around here, but whatever it is, it means trouble. Spelled with a capital 'Harg.' That little monkey didn't knock me cold with his yellow fuzz just for the hell of it. He means business." "I'm afraid," said Sandra seriously, "he intends to do just what he said--and in just as offhand a manner as that in which he mentioned it. To probe our brains for race memories, then dissect us for biological knowledge." "But why?" demanded Larry. "For Lord's sake, why? We're human beings, the same as he. He couldn't kill us in cold blood, just to--" "To him," said Sandra, "we are nothing but a pair of savages. He is not being deliberately cruel, no more so than a Twentieth Century scientist who practices vivisection to add to his knowledge. He is proud of us as an acquisition. May even like us in some cold, inhuman fashion, as we like cats and dogs. But we represent a scientific problem to be solved--and there is no thought in his mind of mercy." "Then," said Larry forcefully, "we've got to pull our freight. Get out of here. But how? That's the rub." "We're helpless against him," mused the girl, "on all save one point. That is the subject he wanted to avoid. Hearing. Larry--Harg can't hear! Not as we understand the word. His ears have atrophied. Or, perhaps--" A sudden light shone in her eyes. "I have it! His ears are--"