the barrier with broken, bleeding finger-tips. To left and right, an arm's length away, were other walls. He was in a pit. The sane part of his brain thought: "Circle around! There may be some way out!" But Vanning could not circle. He could only move in one direction. That was north. He fumbled blindly at the wall, until unconsciousness came at last.... Twice again he awoke, each time weaker, and twice again he slept. The fever, having passed its peak, dwindled swiftly. At last Vanning awoke, and he was sane. No longer did he feel the relentless urge to turn north. He lay for a little while staring into the blackness, realizing that he was once more in full command of his traitorous body. There was little life left in him. His tongue was blackened and swollen till it filled his mouth. He was a scarecrow, nearly naked, his bones sharply defined through his skin. It was an effort even to breathe. But death would not be long in coming—now.... II Dying is an uncomfortable business, unless a man is drugged or insensible. Vanning found it so. Moreover, he wasn't the sort of man who would give up without good cause. Weak as he was, nevertheless he was still too strong to lie in the dark, waiting. Laboriously, he got to his hands and knees and commenced a circuit of the pit. He expected nothing. But, at the southern end of his prison, he was astounded to find a hole in the wall easily large enough to admit his body. Feeling into the blackness, he discovered the smooth floor of a passage. Good Lord! It had been there all the time, during his tortured imprisonment in the pit. If he had only searched before— But he could not have done so, of course. Not with the North-Fever flaming in his veins. The tunnel might lead anywhere. All the chances were against its leading to safety. Sooner or later, there would probably be a dead end. Nevertheless, there was a chance. That chance grew brighter as Vanning's fingers discovered that the walls bore the marks of tools. The tunnel had been made by—perhaps not humans, but at least by some intelligent race! It grew higher as he went on, but Vanning was too weak