That was the first day. The second was worse. The trees were thicker, and sometimes it was necessary to use _machete_-blades to hew through the tangled undergrowth. * * * * * Another day--and another--and another, following the clues on Paula's cipher map. They found the first guidepost, the hill honeycombed with caves, and from there went on to the east, camping at the edge of a ravine that dropped away into unplumbed darkness. Camouflage-moss grew here, looking deceptively like solid ground. One of the men ventured too close to the edge of the cleft, and the moss crumbled beneath him, dropping him into a nest of the roots--twining, writhing cannibalistic serpents with sucker-disks that drank blood thirstily. They got him out in time, luckily. But the men's nerves were jolted. After that, day after day, constant alertness was vital. The party walked with guns and knives in their hands. Their footsteps rang hollow in the dead, empty silence of the Forest.... It was only Garth's knowledge of the dark wilderness that got them through to the interior. After a week, he was further in than he had ever penetrated before, except when he had crashed the air-car with Doc Willard five years ago. But they were getting closer--nearer! More and more often Garth remembered the black notebook that might hold the cure for the Silver Plague. For some indefinable reason he had come to feel that Paula's goal was also his. It was logical enough. They were searching for a lost treasure-house of the Ancient Race, guarded, perhaps, by the Zarno. And Garth was certain that, during that period of partial amnesia, he and Willard had been captives of the Zarno. He had been drugged with the Noctoli poison by day, but at night he had wakened in a bare cell with his friend--a cell with walls of metal, he recalled. It had been windowless. Lighted by a faint glow from one corner. It checked. A ruin, once built by the Ancients, now inhabited by the Zarno. If he could find that notebook-- He always stopped there. He knew what he might also discover--the skeleton of Willard, stretched on an altar. That picture always made his stomach go cold and tight. That night Brown complained of a splitting headache. They camped near a stream, and Garth accompanied the Captain down to the bank, with canvas pails. Jupiter was invisible--they had not seen the sky for a week--but the red light was fading. "Not too close," Garth cautioned. "Let me test it first." Brown stared at him. "What now? I'm getting to expect anything here." The man's expressionless face showed signs of strain and exhaustion. He had no nerves, apparently, but the gruelling journey had told on him nevertheless.