Harker pulled himself up. His ears rang and he shivered uncontrollably, but he could still take some of McLaren's weight on himself. They were climbing a steep ledge, fairly wide and not difficult. "Let's get on," said Harker. About two hundred feet beyond that point the ledge dipped and began to go down again in a series of broken steps. Overhead the cliff face bulged outward. Only a fly could have climbed it. They stopped. Harker cursed with vicious slowness. Sim closed his eyes and smiled. He was a little crazy with fever himself. "Golden city's at the top. That's where I'm going." He started off along the ledge, following its decline toward a jutting shoulder, around which it vanished. Harker laughed sardonically. McLaren pulled free of him and went doggedly after Sim. Harker shrugged and followed. Around the shoulder the ledge washed out completely. They stood still. The steaming clouds shut them in before, and behind was a granite wall hung within thick fleshy creepers. Dead end. "Well?" said Harker. McLaren sat down. He didn't cry, or say anything. He just sat. Sim stood with his arms hanging and his chin on his huge black chest. Harker said, "See what I meant, about the Promised Land? Venus is a fixed wheel, and you can't win." It was then that he noticed the cool air. He had thought it was just a fever chill, but it lifted his hair, and it had a definite pattern on his body. It even had a cool, clean smell to it. It was blowing out through the creepers. Harker began ripping with his knife. He broke through into a cave mouth, a jagged rip worn smooth at the bottom by what must once have been a river. "That draft is coming from the top of the plateau," Harker said. "Wind must be blowing up there and pushing it down. There may be a way through." McLaren and Sim both showed a slow, terrible growth of hope. The three of them went without speaking into the tunnel. II They made good time. The clean air acted as a tonic, and hope spurred them on. The tunnel sloped upward rather sharply, and presently Harker heard water, a low thunderous murmur as of an underground river up ahead. It was utterly dark, but the smooth channel of stone was easy to follow. Sim said, "Isn't that light up ahead?" "Yeah," said Harker. "Some kind of phosphorescence. I don't like that river. It may stop us." They went on in silence. The glow grew stronger, the air more damp. Patches of phosphorescent lichen appeared on the walls, glimmering with dim jewel tones like an unhealthy rainbow. The roar of the water was very loud. They came upon it suddenly. It flowed across the course of their tunnel in a broad channel worn deep into the rock, so that its level had fallen below its old place and left the tunnel dry. It was a wide river, slow and majestic. Lichen spangled the roof and walls, reflecting in dull glints of color from the water.