Shortly after noon the lake ceased growing and began to dwindle. Slowly at first, then with increasing rapidity the water vanished into the sand. There was confusion in Central Camp and at the shores of the pool. By midafternoon it was gone, leaving only an expanse of mud that dried and cracked under the glaring sun. Klev twittered anxiously at this latest development. "He says the Martians have discovered what we did, and set the _vora_ to pumping the water away again," Susan translated. "No matter. The ship is on the way by now." As evening approached Nick wedged a large boulder firmly into the mouth of the tunnel, placed his back against it and announced his intention of sleeping there. "At least we'll know if they come after us," he said. Klev nodded approval. But the Martians made no attempt at reprisal for the humans' interference, as they were too busy preparing their attack on the camp. Next morning truckloads of drilling equipment rolled out from camp, and soon a dozen rigs were boring through the sand and underlying rock. Floodlights were erected and the drilling went on day and night. But the space beacon did not flame again with the news that the water had vanished. Power was too precious. Nick counted the days as he doled out the water from the canteens they had refilled in the underground lake. His concentrated emergency rations, shared with Susan and Klev, gave out at last. The Martian did not drink, but finally the last trickle of water went down Susan's throat and the period of torture began. Nick slept during the torrid days now, panting and itching and thirst-tormented beneath an overhanging rock, and through the nights lay on the edge of the bowl watching the sky. They did not talk much, for the effort hurt their parched throats. It seemed a vision born of wishful thinking when at last the distinctive fan-shaped trail of a spaceship showed against the stars, dim at first but steadily growing brighter. And then it was in the upper atmosphere, the scream of the braking jets rising and falling as the pilot jockeyed the throttles. Down it came in a flaming arc, to land amid the beckoning lights of Central Camp. "What do we do now?" Susan asked. "Steal it." "But how?" Nick shook his head wearily. "Wait for the Martians to attack. Then try to break through." "But the barrier? We'll be killed too, just like the Martians." He looked at her sharply. "I'm going with you, of course." V With full daylight three half-tracks moved out from beside the grounded spacer to the site of the drilling operations. They paused while a group of men got out to inspect the dry holes and the line of stakes that had been placed to indicate the margins of the vanished lake. Then the cars moved on, scouting the surrounding desert.