He seemed to remember collapsing in the shadow of a rocky outcropping, and as he had fainted he had known he was dying. He had been so near dead that his eyes remained vacantly open, and in his unconsciousness he had seen--he thought--strange creatures that were tall and green and somehow _thin_ in consistency. Like Marties. And there had been darkness and coolness after the blazing heat of the desert. Yes, and even wetness, wetness on arid Mars where all water was tanked in from Earth. He couldn't remember, but something had happened. Days later a patrol had found him by chance, and back at Central Camp the medical staff had been skillful. But they were human and had therefore overlooked the obvious fact that he had gone three weeks without Gravinol. And for some reason he himself could not understand he had remained silent, battling the recurrent temptation as he recovered. Something--perhaps bodily dehydration, perhaps heat, perhaps the actinic rays of the sun that had turned his skin almost to leather--something out there on the desert had enabled him to evade the death that usually followed deprivation of Gravinol. One day when he was stronger and the recurring craving had all his nerves screaming, he had called Jake Alaimo out for a barehanded duel and snapped his neck with an edgewise chop of his palm. But when Colonel Hammer had congratulated him he had only felt annoyance. He was beginning to think for himself once more. II A sound in the tunnel broke into his reverie, bringing him instantly to the alert. Soft padding footsteps. He drew his gun and aimed at the sound. "Don't!" Susan's hand dragged his gun down. "It won't hurt us." "Huh?" Indoctrination had taught that everything that moved upon Mars was hostile, to be killed on sight. The impulse was still strong. "It's a _cajora_. The Martians keep them as pets," she insisted. Nick's scalp crawled as the big animal glided through the darkness and its coarse fur made sandpaper sounds against Susan's legs. He had seen the six-legged beasts on the surface, large as Earth tigers. "_Mel nikko twa Klev_," Susan said soothingly. "_Mel nikko twa Klev?_" The creature purred. Nick kept his gun ready and swung toward the girl. She could feel him tense with suspicion. Indoctrination had impressed upon Nick's mind the story that Jackson Jones and his daughter had turned traitor to Earth, siding in with the dangerous and degenerate Marties. "What'd you say?" he asked. "That's Martian." Her answer was matter-of-fact. "I asked him where Klev is." "Martian?" Nick was astonished. "Have they a real language? Then they're really intelligent?" He had suspected but hadn't known. "Of course," she whispered. "Ssh! You're disturbing the _cajora_." "What's Klev? What do you want?" "He's a Martian. My friend," she answered, and talked to the _cajora_ again as though it were a dog or cat.