* * * * * Breakfast over, they started down the valley, Stevens carrying his helmet under his arm. Hardly had they started however, than Nadia's keen eyes saw a movement through the trees, and, she stopped and pointed. Stevens looked once, then hand in hand they dashed back to their cave. "We'll pile up some of the boulders and you lie low," he instructed her as he screwed on his helmet. She snapped open his face-plate. "But what about you? Aren't you coming in, too?" she demanded. "Can't--they'd surround us and starve us out. I'm safe in this armor--thank Heaven we made it as solid as we did--and I'll fight 'em in the open. I'll show 'em what the bear did to the buckwheat!" "All right, I guess, but I wish I had my armor, too," she mourned as he snapped shut his plate and walled her into the cave with the same great rocks he had used the night before. Then, Nadia safe from attack, he drew his quiver of war-arrows into position over his shoulder, placed one at the ready on his bow-string and turned to face the horde of things rushing up the valley toward him. Wild animals he had supposed them, but as he stood firm and raised his weapon shrill whistles sounded in the throng, and he gasped as he realized that those frightful creatures must be intelligent beings, for not only did they signal to each other, but he saw that they were armed with bows and arrows, spears, and slings! Six-limbed creatures they were, of a purplish-red color, with huge, tricornigerous heads and with staring, green, phosphorescent eyes. Two of the six limbs were always legs, two always arms; the intermediate two, due to a mid-section jointing of the six-foot-long, almost cylindrical body, could be used at will as either legs or arms. Now, out of range, as they supposed, they halted and gathered about one who was apparently their leader; some standing erect and waving four hands while shaking their horns savagely in Stevens' direction, others trotting around on four legs, busily gathering stones of suitable size for their vicious slings.