“That is how you knew I would come to you? How well do I remember! But then, as before, you slipped away from me. I have a terrible fear you will fade away, leaving me but a dream to remember you by.” “No, no, no!” she cried earnestly; and then, as if suddenly embarrassed by the subtle admission just made, she flushed and turned away. As they walked quietly back toward the _Sphere_ where the others waited there was a song in Robert’s heart. * * * * * Once more they embarked on their journey toward the polar region. The gyrostats now operated faultlessly. Robert rose slowly to an altitude of about 2,000 feet. Since their arrival on Mars Robert and Professor Palmer had established the existence of the canals, or ducts, thereby settling for all time--provided they succeeded in returning safely to Earth--the controversy over the most noted characteristic of Mars as seen from the Earth, the curious network of lines. Incidentally, they had seen the Martian deserts as well as both rural and city life on the planet. They were informed as to the correctness of their original conjecture as to the method of pumping the water from the poles to all sections of the globe. This was accomplished by means of electric pumping stations at intervals along each duct, the rays of the sun being absorbed and converted into electric energy for this purpose by the big checker board structures. But the feature which, so far, had defied plausible explanation by all experts of our world, still remained a riddle to the adventurers. This was the “carets,” or triangular-shaped points which existed wherever the canals were seen to connect with one of the large, shaded regions. These shaded regions also were a riddle. A theory that the latter were seas was exploded by the fact that in some instances the canal lines were visible running across them. For another thing it was agreed by practically all experts that the seas on Mars had long since dried up. It was, therefore, with considerable excitement that Professor Palmer observed that they were nearing one of these regions. From a height of several thousand feet one of the “carets” could be seen plainly as they approached it. As Robert lowered the _Sphere_ toward it, Hakon showed signs of uneasiness. Still he held his peace until it became quite evident to him that his hosts intended approaching close to this section. Zola, too, was evidently perturbed. “There is danger there, gentlemen,” said Hakon, finally. “I beg of you, do not go too close.” “What is it?” questioned Professor Palmer, now intensely interested. Both he and Robert received the impression that some terrible physical force connected with the phenomenon threatened their safety. But in this they were quickly disillusioned by Hakon.