They shook hands solemnly after Peetn had dumped his load of food, and the stranger drew Peetn over to a patch of cleared sand. Bending down, he drew with his finger a crude diagram of the water-station, pointing to it, and then to the reservoir, pump-cavern, and the valve-house, indicating each in the sand in turn. He then drew a line from the pump-cavern northward, and connected it to a large scrawl which Peetn decided was supposed to represent the ice-cap. He nodded his head in a gesture which he had learned from the Earthman, indicating that he understood, and that the diagram was right. Clark then drew a line from the valve-house south. By means of much pointing and insistent signs, the Martian finally discovered that he wished to know where it led, and what was at the end. Peetn jack-knifed his gangly legs and sank to his knees. The tip of his tentacles traced a picture in the sand. It looked like a series of small circles interlinked by little curved lines. Peetn pointed to himself, then at the circles. Then he made eighty-two little dashes in the sand. The Earthman understood immediately. So that was it! This water-station supplied a colony of eighty-two Martians with drinking water, vital to their existence! They must live very far south near the equator, in the warmest zone of the planet, where food and heat were more abundant. Of course! And Beany was shipped up here as watchman. Clark looked with new respect at the Martian, thinking of the soul-deadening loneliness he must have known. He certainly wasn't much good as a mechanic; why, he couldn't even have known that the flow of water could be increased by opening those valves wider! Naturally, he had thought that Clark had tried to sabotage the plant when he had laid hands on the machinery. Those pumps--it was a wonder that they hadn't frozen stiff long before this. Harrison Clark made up his mind. Next morning when Peetn arose, the man from Gamtl was gone. So was a three-day supply of _merrl_ and water. * * * * * It was eight days later when the Martian emerged from the valve-house and saw the tiny figure come trudging out of the west. It was the alien, and behind him dragged a curious object, a black, cylinder-like affair trundling along on four wheels and pulled by a rope in the stranger's hands. Peetn stalked out to meet him and after they had shaken hands, he curled a few tentacles about the rope and together they pulled the mysterious object into the water-station. Peetn watched with his curiosity aroused as Clark heaved and grunted the thing down the thirty-one steps into the underground pump room, talking all the while.