The Qul-En vehicle halted. The flock had been counted; now to select specimens and get to work. There were six new animal types to be dissected for the nervous organ yielding the looked-for hormone. Four kinds of sheep--male and female, and adult and immature of each kind--the biped, and the dog. Then a swift survey to estimate the probable total number of such animals available, and--. Antonio saw that the devil mountain-lion was still. He got down on one knee, fervently crossed himself and fed a cross-marked bullet into the chamber of his rifle. He lined up the sights on the unearthly creature. The lion-facsimile watched him interestedly; the sight of a rifle meant nothing to the Qul-En, naturally. But the kneeling posture of the man was strange. It was part, perhaps, of the pattern of conduct which had led him to start that oxidation process about the deer-specimen. Antonio fired. His hands trembled and the rifle shook; nothing happened. He fired again and again, gasping in his fear. And he missed every time. The cross-marked bullets crashed into red earth and splashed from naked rock all about the Qul-En vehicle. When sparks spat from a flint pebble, the pilot of the mountain-lion realized that there was actual danger here. It could have slaughtered man and dog and sheep by the quiver of a tentacle, but that would have ruined them as specimens. To avoid spoiling specimens it intended to take later, the Qul-En put the mountain-lion shape into a single, magnificent leap. It soared more than a hundred feet up-hill and over the crest at its top; then it was gone. Salazar ran barking after the thing at which Antonio had fired, sniffed at the place from which it had taken off. There was no animal smell there at all. He sneezed, and then trotted down again. Antonio lay flat on the ground, his eyes hidden, babbling. He had seen irrefutable proof that the shape of the mountain-lion was actually a fiend from hell. 3 Behind the hill-crest, the Qul-En moved away. It had not given up its plan of selecting specimens from the flock, of course, nor of anatomizing the man and dog. It was genuinely interested too, in the biped's novel method of defense. It dictated its own version of the problems raised, on a tight beam to the wavering, color-changing flame. Why did not the biped prey on the sheep if it could kill them? What was the symbiotic relationship of the dog to the man and the sheep? The three varieties of animal associated freely. The Qul-En dictated absorbed speculations, then it hunted for other specimens. It found a lobo wolf, and killed it, verified that this creature also could be a source of hormones. It slaughtered a chipmunk and made a cursory examination. Its ray-beam had pretty well destroyed the creature's brain-tissue, but by analogy of structure this should be a source also.