The scientist strode toward the deeper darkness of the entrance and shot his light inside. The others took up the positions he had assigned. Rick kept his flashlight beam moving around the big cave, watching for any sign of an enemy.

"Another passage," Zircon said, and his voice echoed hollowly. "Cover our rear, Rick." They went into it single file, Rick walking sideways in order to keep looking back for a possible enemy. Then, as the others stopped suddenly, he fell over Chahda. He heard the scientist say, "Dead end. Nothing but a blank wall. Rick, lead the way out. We'll try the other."

The second passage gave better results. It wound through the limestone for a short distance, then opened into a small cave filled with wonderful white rock formations.

"Stalactites and stalagmites," Zircon boomed. "I suspect we are getting into the deeper caverns, those hollowed out by water and not by man. The question is, which way do we go now?"

Rick took his eyes from the way they had come long enough to look around. The cave was like a junction room, openings branching off in all directions.

Scotty switched on his flashlight and began examining the cave floor. "Look for signs," he directed. "If men have come this way, they must have left some traces."

Chahda hurried to look, too. Rick stood where he was, light and eyes going from one opening to another. He didn't intend to be caught off guard.

Scotty gave a grunt of satisfaction and stood up. "Candle wax," he announced. "And it leads through here." He pointed to a gap between two fluted columns, made by centuries of dripping water that had deposited countless grains of limestone.

Zircon immediately walked to the gap and peered through. "Come on," he said. "There's another cave beyond."

The next cave was larger, and nowhere in it was there evidence that man had occupied it. Rick looked around him, awed by the bizarre beauty of the place. From ceiling and floor limestone icicles strained toward each other. They were the stalactites and stalagmites Zircon had mentioned, formed over the centuries by slow drops of water, each of which left its tiny trace of limestone to help build up the formation. On one wall of the cave the water deposits had carved a waterfall, so perfect that it might have been frozen into white rock only moments before. And from every grain of stone their flashlight beams twinkled and reflected until it seemed the walls were crusted with jewels.