No Zeudian was in sight. Evidently they were too sure of their poison glands to post a guard over them. He listened intently, and could hear no dragging footsteps. He turned to Wichter, who had followed his example and was sitting up, feebly rubbing his body to restore circulation. "Now's our chance," he whispered. "Stand up and walk a little to steady your legs, while I go over and get us a couple of those sharp horns. Then we'll see where that entrance of mine goes!" He walked to the pile of bones and horns in the corner and selected two of the longest and slimmest of the ivory-like things. Just as he had rejoined Wichter he heard the sound with which he was now so grimly familiar--flapping, awkward footsteps. Wildly he signaled the professor. They dropped in their tracks, just as the approaching monster stumped into the cave. * * * * * For an instant he dared hope that their movement had gone unobserved, but his hope was rudely shattered. He heard a sharp hiss: heard the Zeudian flap toward them at double-quick time. Abandoning all pretense, he sprang to his feet just as the thing reached him, its fangs gleaming wickedly in the greenish light. He leaped to the side, going twenty feet or more with the press of his Earth muscles against the reduced gravity. The creature rushed on toward the professor. That game little man crouched and awaited its onslaught. But Joyce had sprung back again before the two could clash. He raised the long horn and plunged it into the smooth, purplish back. Again and again he drove it home, as the monster writhed under him. It had enormous vitality. Gashed and dripping, it yet struggled on, attempting to encircle Joyce with its stubby arms. Once it succeeded, and he felt his ribs crack as it contracted its powerful body. But a final stroke finished the savage fight. He got up and, with an incoherent cry to Wichter, raced toward the opening on which they pinned their hopes of reaching the upper air. Hissing cries and the thudding of many feet came to them just as they reached the arched mouth of the passage. But the cries, and the constant pandemonium of the paralysed animals died behind them as they bounded along the tunnel. * * * * * They emerged at last into the sunlight they had never expected to see again, beside one of the great lavender trees. They paused an instant to try to get their bearings. "This way," panted Joyce as he saw, on a hard-packed path ahead of them, one of the trail-marks he had blazed. Down the trail they raced, toward their space shell. Fortunately they met none of the tremendous animals that infested the jungles; and their journey to the clearing in which the shell was lying was accomplished without accident. "We're safe now," gasped Wichter, as they came in sight of the bare lava patch. "We can outrun them five feet to their one!"