"Well," said Stokely, his voice harsh and a trifle high-pitched, "where's the jade?" He deliberately pointed his gun at the doctor, who regarded him dubiously. "I'm sure it's here," said Dr. Grimwood, "but I really don't know much about its appearance in the natural state. They carefully avoided any mention of that on their map, you know. That map was intended for them alone." The doctor began to walk slowly among the rocks, studying them. "I seem to recall, though, hearing something about--" He paused, bent down slowly with the weight of his pack, and dug with his space-gauntleted fingers at a hollow in one of the larger rocks. "--moss!" he finished. "Gray moss. I think this is it." The tufted moss was hardly distinguishable from the stone itself in the waning light. Dr. Grimwood plucked from its core a thimble-sized lump. Holding it up, he scraped away part of the gray coating. It was as if, with some magic flint, he had struck green fire. The eerie glow of the gem made the surrounding area seem suddenly darker by contrast. Will Archer only glanced at it, returning his gaze quickly to Stokely, on his left. In the big man's reaction to this climactic discovery might lie some clue to his probable course of action. And the expression on Stokely's face was not good to see. The pale eyes which had widened at the first sight of the gem now narrowed to slits, while his normally regular features pulled into an ugly mask. A dark flush suffused his freckled cheeks. Archer watched him with growing alarm. There was little doubt that, for the moment, Stokely was not sane. His gun, still pointed at Dr. Grimwood, moved slightly, and Archer saw his finger tightening on the trigger. In one motion, Archer slipped free of his pack and flung himself at the heavier man. The gun went off just as he struck, and Stokely, caught off guard, was bowled over like a tenpin. His head-globe hit hard against the rocky ground, protecting his head but smashing a large hole in the globe. He went over so easily that Archer himself was thrown off balance. He stumbled over Stokely's legs and fell a few feet beyond. Rolling over quickly, he scrambled to a crouching position, then paused, and drew himself slowly erect. Evans was standing just beyond Stokely, and the gun in his hand was aimed steadily at Archer's stomach. Dr. Grimwood was lying prone and limp, his blood trickling out between the stones under him, the bit of jade glinting near his outstretched hand. Stokely picked up his gun and got to his feet dazedly, shaking his head to clear it. Archer studied his face and saw there a vast, rising anger, but no longer the wild light of utter unreason. The man was in a dangerous mood and might readily kill again, but he had evidently been jolted back to a semblance of sanity.