Cautiously, he swung one arm out as far as he could reach. There was nothing there. He moved the arm down; reached with his hand beneath him--and still there was nothing tangible! Through his mind swept a gripping fear, a wordless, incoherent terror of something he could not name. Desperately he wanted to touch something firm and solid; lay his hands upon something he knew was real; and he flung out arms and legs in a paroxysm of futile effort. He seemed hung in nothingness, an utter emptiness where nothing moved; only the ghostly whirls of light that ran lazily away from his beating hands until they died silently away into darkness, swallowed up in this unspeakable horror of soundless space. And, when he had quieted again, he knew with a dreadful certainty that there was nothing there; he was suspended in a great void--immersed in an ocean of some unknown gas. The sense of loneliness that filled him was devastating. He could have faced death as he had faced it before, unflinchingly; that was all in the day's work. But here was something that tested sanity itself. Could he but touch something substantial, he told himself, it would help him to keep a grip on reality; even to see and feel one of the winged horrors would be in a way a relief. * * * * * His struggles had ceased; all about him the atmosphere was quivering and writhing with whirling light that swirled and danced and mingled one glowing vortex with another. Then it, too, died; and, through the dark that was relieved only by the faint luminosity of the quiescent gas, he saw far off a point of light. Here was something to which he could pin his eyes; something outside of himself and the horror of nothingness in which he was immersed. He stared through the window of his helmet while the light grew and expanded into nebulous, cloudy glowing that faded and was gone. Again it came and died; and a third time. And then Chet Bullard swore loudly and harshly within the silence of his own metal sheath, while he cursed his own dullness that had kept him from instant comprehension. That light was far away, but, "Keep moving!" Chet called, hoping that his voice might span the void. "Keep moving so I can see your light! I'll try to swim over." He threw himself over with a convulsive jerk and flattened the palms of his hands in a breaststroke, while he kicked with his feet against the dense atmosphere about him. And he saw with delight that the whirling ripples of light moved back of him; he felt that he was making some headway, slight though it must be. * * * * * He saw her at last, and heard her call: "I am swimming, too," she cried. "How wonderful to see you! This loneliness! It is horrible--unbearable!" "I understand," Chet said; "it is pretty bad."