Tommy reached the third bend in the Tube. By now he had lost all sense of orientation. An object may be bent through one right angle only in two dimensions, and a second perfect right angle--at ninety degrees to all former paths--only in three dimensions. It follows that a third perfect right angle requires four dimensions for existence, and four perfect right angles five. The Tube bent itself through four perfect right angles, and since no human-being can ever have experience of more than three dimensions, plus time, it followed that Tommy was experiencing other dimensions than those of Earth as soon as he passed the third bend. In short, he was in another cosmos. There was a moment of awful sickness as he passed the third bend. He was hideously dizzy when he passed the fourth. For a time he felt as if he had no weight at all. But then, quite abruptly, he was climbing vertically upward and the soughing of tree-fern fronds was loud in his ears, and suddenly the end of the Tube was under his fingers and he stared out into the world of the Fifth Dimension. Now a gentle wind blew in his face. Tree-ferns rose to incredible heights above his head, and now and again by the movements of their fronds he caught stray glimpses of unfamiliar stars. There were red stars, and blue ones, and once he caught sight of a clearly distinguishable double star, of which each component was visible to the naked eye. And very, very far away he heard the beastly yellings he knew must be the outlaws, the Ragged Men, feasting horribly on half-scorched flesh torn from the quivering, yet-living flanks of a monstrous reptile. Something moved, whimpered--and fled suddenly. It sounded like a human being. And Tommy Reames was struck with the utterly impossible conviction that he had heard just that sound before. It was not dangerous, in any case, and he watched, and listened, and presently he slipped from the mouth of the Tube and by the glow of a flashlight stripped foliage from nearby growths and piled it about the Tube's mouth. And then, because the purpose of the Tube was not adventure but science, he went back down into the laboratory. * * * * *