An hour later Brett had traversed the second cavern. Now he clung to an outthrust spur of granite directly beneath the point at which Dhuva had disappeared. Far above he could see the green-clad waitress standing stiffly on her ledge. He was tired. Walking in water, his feet floundering in soft mud, was exhausting. He was no closer to escape, or to finding Dhuva, than he had been when the fat man cut the rope. He had been a fool to leave the man alone, with a knife ... but he had had no choice. He would have to find another way out. Endlessly wading at the bottom of the pit was useless. He would have to climb. One spot was as good as another. He stepped back and scanned the wall of clay looming over him. Twenty feet up, water dripped from the broken end of a four-inch water main. Brett uncoiled the rope from his shoulder, tied a loop in the end, whirled it and cast upward. It missed, fell back with a splash. He gathered it in, tried again. On the third try it caught. He tested it, then started up. His hands were slippery with mud and water. He twined the rope around his legs, inched higher. The slender cable was smooth as glass. He slipped back two feet, then inched upward, slipped again, painfully climbed, slipped, climbed. After the first ten feet he found toe-holds in the muddy wall. He worked his way up, his hands aching and raw. A projecting tangle of power cable gave a secure purchase for a foot. He rested. Nearby, an opening two feet in diameter gaped in the clay: a tunnel. It might be possible to swing sideways across the face of the clay and reach the opening. It was worth a try. His stiff, clay-slimed hands would pull him no higher. He gripped the rope, kicked off sideways, hooked a foot in the tunnel mouth, half jumped, half fell into the mouth of the tunnel. He clung to the rope, shook it loose from the pipe above, coiled it and looped it over his shoulder. On hands and knees he started into the narrow passage. * * * The tunnel curved left, then right, dipped, then angled up. Brett crawled steadily, the smooth stiff clay yielding and cold against his hands and sodden knees. Another smaller tunnel joined from the left. Another angled in from above. The tunnel widened to three feet, then four. Brett got to his feet, walked in a crouch. Here and there, barely visible in the near-darkness, objects lay imbedded in the mud: a silver-plated spoon, its handle bent; the rusted engine of an electric train; a portable radio, green with corrosion from burst batteries. At a distance, Brett estimated, of a hundred yards from the pit, the tunnel opened into a vast cave, green-lit from tiny discs of frosted glass set in the ceiling far above. A row of discolored concrete piles, the foundations of the building above, protruded against the near wall, their surfaces nibbled and pitted. Between Brett and the concrete columns the floor was littered with pale sticks and stones, gleaming dully in the gloom.