Sue talked to the Martian, who nodded and began to trace a complicated diagram in the sand with one finger, hesitating before adding each line as though resurrecting old and almost forgotten memories. * * * * * Nick watched a while. Then a patrol rocket whistled over heading south, and after it had passed he climbed once more to the rim of the bowl. He watched it settle inside the barrier with a flare of braking jets and a cloud of red dust. And while he watched he thought. To go below for water was absolutely necessary, but a purely defensive action which could at best only postpone the end. And nothing had ever been won by defensive action alone. Pure defense always meant eventual defeat. He thought some more, then scrambled hurriedly down the rocks just as Klev completed the diagram. "Sue," he panted, still out of breath. "Those creatures bred to tunnel and pump water. Are they still alive? Is there any way to make them work? Ask him!" Sue hesitated, not understanding. "Can they pump water up as well as down? Ask him!" Nick barked impatiently. Suspicion showed in the Martian's manner as Sue made the request. "He won't answer until he knows what you're planning," she reported. "If the Exploiters found water they'd never leave." "One of us has to get back to Earth." Nick tried to be as patient as possible. "After everything that happened during the War years you can be damned sure the New Governments would handle Harmon fast and tough--if they knew what he is doing and planning. We need a ship, but when the next supply ship comes out eight weeks from now it will be too late. We've got to get a ship out _ahead of schedule_, and only one thing will do it. Water!" "But how can you get--?" "I'm not sure, yet," he admitted. "But it's worth a chance. Now ask him again." The Martian looked doubtful. For a moment his hand hovered over the chart in the sand as though to erase it. "Give him time," Susan advised. "It's a gamble," Nick admitted. "But the _voras_--" "Live almost forever," she responded. "Whether we could make them work for us--" The sun was almost down before Klev decided, but then he chirped and clicked for a good three hours. The water caves could be reached, he said, but some of the _vora_ burrows through which they must crawl were so small it would be impossible to carry him, and his own strength was insufficient. And the distance from the water caves to the surface was too great for him to reach the water-_voras_ by thought alone, the usual method. "You made the screen-_vora_ work," Nick reminded Susan. She was uncertain. "Water-_voras_ are different. But I'll try." The moon shadows were too black to permit them to study Klev's chart during the night. Klev slept, with the patience and resignation only age can bring. Once or twice Sue nodded in Nick's arms, but he remained fully awake, thinking.