Captain DeCastros was taking his time now, resting frequently. There was not the slightest chance of Malmsworth's getting away, for at the other end of the rift lay the cave and the abyss containing, at least, one ghost of Malmsworth's terrible past. But though it might seem drab after the plateau and the plain, the rift had its points of interest. Along the walls, everywhere, as high as a tall man might reach, the moss had been torn or scraped from the surface. There was no second growth. * * * * * Every quarter of a mile or so they came upon the former campsites of the castaway, each marked by a flat-topped cairn of small stones three or four feet in height. DeCastros was at a loss to explain this. Mr. Wordsley supposed that it was one of the marks of a diseased mind. Not that he actually understood the workings of a diseased mind. Privately, he suspected that DeCastros was a little mad. Certainly he was subject to violent, unreasonable tempers which could not be explained. The unfortunate strain might have cropped up more strongly in his brother. Might not these walls have rung with lunatic screams after months and years of hollow-eyed watching for the ship that never came? It might have been different, of course, had Malmsworth been able to appreciate the aesthetic values of life, as Mr. Wordsley did. But doubtless these lovely miles and miles of crystalline oceans had been but a desert to the castaway. Eventually the rift widened a little, and they came to a dead end, beyond which lay the cave. It must have been formed ages ago by trickling waters before Avis Solis lost its clouds and rivers. Here they found the last of the cairns, and the answer to their construction. The water-maker which the expedition had left with Malmsworth seventeen years ago rested upon this neat platform, and below it a delicate basin, eighteen inches or so in depth, had been constructed of stones and chinked with moss. Fit monument for the god, machine. It was filled with water, and quite obviously a bathtub. * * * * * Captain DeCastros sneered. This proved beyond doubt that Malmsworth was mad, for in the old days he had been the very last to care about his bath. In fact, DeCastros said, Malmsworth occasionally stank. This was probably not true, but it seemed curious, nonetheless. Captain DeCastros set to work kicking the tub to pieces. He kicked so hard that one stone whistled past the head of Mr. Wordsley, who ducked handily. Soon the basin lay in rubble, and the water-maker, its supports collapsed, listed heavily to the right. "He must be in the cave," Captain DeCastros said. He cupped his hands to his mouth. "Come out, Malmsworth, we know you're in there!" But there was no answer, and Malmsworth did not come out, so Captain DeCastros, blizzer in hand, went in, with Mr. Wordsley following at a cautious interval.