Rick sat with his back against the cold surface of a stalagmite column. His head drooped with weariness and his throat ached from yelling. He had retraced his steps a dozen times or more. He had lost count. But none of the passages took him back to his friends, nor had his yelling of their names brought a response.

He forced himself into a semblance of calmness and tried to think. What was he to do? He eyed the beam of his flashlight and realized that he ought to conserve the batteries. He turned it off, and dead, silent blackness closed in about him.

True blackness is rare. It cannot be found by closing shutters or curtains in a room, even at night. Some light always penetrates man-made rooms unless they are designed, as very few are, for total darkness. Rick never had experienced it before, and it was frightening. He had to take a firm grip on himself to keep from getting panicky.

But if the underground caverns were completely without light, they were not completely without sound. As Rick sat quietly he began to hear the slow drip of water. It was the slow drip of centuries that had produced the weird limestone formations of the caves.

He began to talk quietly to himself, and the sound of his own voice was better than listening to the slow dripping of water.

“I can’t stay here. The others wouldn’t have any more chance of finding me than I have of finding them. But if I leave here, I’m taking a chance. I might go so deep into the caves that I’d never find my way out again, or see any of the others again.”

He had visited some of the limestone caverns of Virginia, and he had read of the New York and Kentucky caverns. He knew that even in America there were endless series of caves that never had been fully explored. This fabled Tibetan place might extend on forever.

“On the other hand,” he continued to himself, “if I keep moving, I might stumble on the big cave under the Black Buddha again. It’s less than a fifty-fifty chance. A whole lot less. But it’s a chance and I’d better take it.”

He didn’t let himself think of what would happen if he failed to find his way back. He got to his feet and switched on his light again. By contrast with the total darkness, the reflection of the beam on the limestone walls was brilliant sunlight. He had to wait while his eyes adjusted themselves to the light. Then he flashed the beam around. There were passages going in every direction.

“Which way do I go?” he asked himself.

It was a tossup. He remembered an old trick and spat into the palm of his hand. Then, with the forefinger of his other hand, he slapped the spittle sharply. The biggest drop flew between two limestone hour-glasses that formed one passage. He hitched up the camera case on his shoulder, picked up his rifle, and started forward.

The caverns were endless. Walking slowly, to conserve his strength, he wandered through countless incredible rooms of gleaming stone. The dripping water had formed all manner of things. He saw animals, ships, mountain scenes, waterfalls, and cataracts, fairy grottoes, fish, distant houses ... all carved of shining stone by millions upon countless millions of water drops over centuries past number. He was so completely enthralled by the unearthly beauty of the place that he even forgot his predicament for a few moments.

And then he noticed that his flashlight was growing so weak that it no longer threw a clearly defined beam. It must have been getting weaker for some time, he thought, but his eyes had adjusted themselves to the failing light.

He looked at his watch, wondering that the flashlight batteries had run down so soon. The watch had run down, too, and had stopped. He couldn’t remember. Had he wound it before coming to the cave? He was chilled now. It was cold and damp in the limestone passages. He shivered and pulled up his collar.

The panic rose up again. He didn’t know how long he had been in the cave. Had it been only a short while, or so many hours that his watch had run down? He said to himself as calmly as he was able, “I’ll have to get where I’m going before the light fails altogether.”

He began to run.

The illusion grew that he was trying to overtake the end of the flashlight’s beam. When he did catch up with it, that would be the end. He had completely forgotten the infrared light on the camera, even though the case banged against his side as he ran. He had been carrying it for so long it had become a part of him.

He dodged through passages, rounded turns, leaped over stalagmites. Once he had to crawl on his hands and knees under water-smooth limestone, pushing his rifle ahead of him.

And all the time he was catching up to the end of the light. The radius of illumination narrowed as the batteries failed, increasing the danger of stumbling into a sudden crevice. Outside, the flashlight would have been rejected long ago as a source of light. But far underground, with no other light of any kind, it was still useful.

Running more slowly now, at a stumbling dogtrot, he broke into a cave larger than any he had seen since the first one, at the end of the passage from the Black Buddha. The feeble light failed to reach the opposite wall.

Rick stopped, panting for breath. He knew he had to rest. He found a natural seat next to a twisted pillar of limestone and sat down.

The light slowly faded until there was only the dimmest of red tints to the bulb, and then that vanished too, and he was again in total darkness. As he watched the light fade, he remembered the infrared. Now he got the glasses from the case and put them on. He took the camera out and adjusted the handstrap so it could be carried like a satchel. But he didn’t turn on the light just yet. The battery had to be conserved at all costs. Because....

He swallowed hard. Because when the battery for the infrared light ran down, there would be nothing but darkness. Darkness would mean feeling his way through the limestone tangle, and he realized fully that he would not get far before death claimed him in the form of a yawning canyon in the limestone rock. He had passed many of them.

He set his jaw. That was ten hours away, because the battery would last that long. Ten hours was a long time if used wisely.

He closed his eyes and leaned back, dead tired. He dozed off.

Rick was never sure what awakened him, because there was no noise. It may have been the light on eyes made sensitive by ultimate blackness. But could a single candle have that much effect?

The candle was carried by a man. A Tibetan. The candle was in a tin container, punched full of holes. That was to keep it from being blown out in case of a draft, although there was little or no draft in the caverns.

When Rick opened his eyes the man was walking straight across the floor of the big cave, noiseless as a cat in feet wrapped in quilted cloth. The miracle was that Rick didn’t cry out on seeing another human.

He sat frozen, watching the man. Then, as the stranger reached the far side of the cave, Rick came to life. If he lost this man, who obviously knew his way around, he was finished! Working at top speed he untied his shoelaces and slipped off his shoes. Then, in stocking feet, he padded silently across the floor.

The candle was his guide. He didn’t need the infrared beam yet. He would follow the candle, and if it led him right into the hands of the enemy, that was better than perishing alone of hunger in the blackness of the inner caves.

As he went, wary of a backward look by his quarry, he put his rifle under his arm and fumbled to tie a knot in his laces. It took time, since he was carrying the camera in one hand now. When he finally managed, he draped the shoes around his neck.

A dozen times he had been on the verge of abandoning the rifle as useless extra weight. Now he was glad he had held onto it.

Ahead, the candlelight bobbed and turned as the Tibetan, unaware that he was being followed, made his way through the caverns. Rick followed at a safe distance, close enough to avoid being left behind by a sudden turn.

There was a new feeling in the air suddenly, a feeling of space and of wetness. Rick sniffed. There was an odor, too, like decaying leaves, although much weaker. His hopes brightened. Was the Tibetan leading him out of the caves?

Then, so suddenly that he almost slipped from the edge, the path took him to a narrow ledge above a body of water of some kind.

The Tibetan was making his way along the ledge, candle held high in a search for something. When Rick switched on the infrared light for a moment, the incredible scene leaped to his eyes from the darkness. From under his feet a lake stretched away, its farther shore beyond the eight-hundred-yard range of the infrared light. He turned the light back and forth, seeking the end of the amazing body of water. But there was nothing except the shore on which he stood.

The water was dead calm. Not a ripple disturbed the glassy surface. He shot the invisible light straight down, and the water was so deep it looked black.

With a sudden start he realized he might lose the Tibetan candle bearer. He hurried after him, using the infrared light because the candle was too far away now to show him the path. With the glasses on, using the infrared light was just like using a powerful searchlight.

Far ahead, the candle stopped moving. Rick now proceeded more cautiously, and he switched off the infrared light in case the Tibetan should look back and possibly spy the glowing filament of the lamp.

The man was stooping over something, the candle resting on the stone next to him. Rick switched the light on, then off again. And he broke into a silent run. During the second the light had been on he had seen that the Tibetan was untying a boat!

He had an instant to make a decision. He reached a spot a few feet behind the preoccupied stranger, who was having trouble with the rope knot, and put the infrared camera down on the stone. Then, gripping the rifle firmly, he walked right up to the man.

“Hands up,” he growled.

The Tibetan screamed.

He whirled, eyes wide with astonished fright, and he didn’t even see the rifle. He swept an enormous knife from his belt and leaped!

Rick stumbled backward, and as he did, he realized that he couldn’t shoot. He still needed the man for a guide. He swung the rifle, barrel first.

It was just as effective as it had been when he swung on Worthington Ko. The barrel connected with an audible thunk. The Tibetan fell forward on his face.

Frightened out of his wits, Rick rolled him over, pulled aside the sheepskin coat he wore and put his ear on the man’s chest. Then he sighed with relief. He hadn’t swung too hard. For a moment he had feared that the blow had killed the man. And that would have been almost as effective as holding the rifle barrel to his own head, because he still had no idea of where to go without the guide.

He debated for a moment, then lifted the Tibetan, dragged him to the boat and dumped him in. It was a flat-bottomed craft with blunt ends and primitive oar-locks. The oars were poles with round disks of wood on the ends.

He collected the candle and the camera, placed them on a thwart, and went to work on the rope. It was reeved through an iron ring that jutted from the stone. The sight gave him heart. Where there was iron, men came often. At least he was sure that held true in this case. But his victory had spurred him on and he didn’t want to sit quietly and wait. He wanted to keep going.

He untied the knot, blew out the candle, shipped the oars and pushed off. Something was on the other side of this Lake of Darkness. He couldn’t imagine what, but he intended to find out!