The front chamber of the cave was somewhat semi-circular, and behind this were several other irregular apartments, running down to a passageway which wound in and out between jagged rocks almost impossible to climb or explore in any manner. At a distance could be heard the trickling of water, but where this came from, or where it went to, nobody in the cave could imagine.

The boys advanced from one opening to another with care, one with his torch held high, that they might see ahead, and the other with the light close to the ground, to warn them of a possible pitfall.

"A regiment of soldiers could quarter in here," observed Darry, as they pushed on. "What a defense it would make!"

"An enemy could fire right into the entrance. And, besides, supposing the enemy started to smoke you out? I can smell the smoke from the camp-fire away back here."

At last the two boys reached the passageway back of the rear chamber, and here came to a halt. The dropping water could be plainly heard, and Joe flashed his torch in several directions in the hope of catching sight of the stream.

"I'm going to climb the rocks," he said, after a pause. "Perhaps there is another opening behind them."

"Remember what Benson said, and be careful," cautioned his cousin. "There is no use in taking a risk for nothing."

"Yes, I'll be careful," answered Joe, and crawled forward with care. Darry held his torch as high up as possible, to light the way.

The youth had advanced a distance of fifty feet when he came to a turn in the passageway. Here the side walls were not over two yards apart, while the roof could be touched with ease.

Thinking the walking better at this point, Joe struck out once more. The flare from his torch showed him something of a chamber ahead, and the water sounded closer than ever.

But hardly had the lad taken a dozen steps when the smooth rock upon which he was advancing tilted up, sending him headlong. As he went down the torch was knocked from his hand. Then he slid forward into the darkness.

"Help!" he managed to cry. "Help!"

"What's up?" came from Darry, but the words were drowned out in the crashing of one stone against another. In the meantime Joe had fallen, he knew not whither. He landed on some soft ground, turned over and slid along, and then took a second drop. A stone fell beside him and pinned his jacket to the ground.

For the moment the lad was too dazed and bewildered to do anything but try to get back his breath. Then, as it gradually dawned upon him that he was not hurt in the least, he endeavored to arise.

"Fast!" he muttered, and tore his jacket away from under the rock. Then he turned about, trying to locate his torch. But that was missing, and all was dark around him.

"I'm in a pickle now," he thought. "I wish I had taken old Benson's advice and remained around the camp-fire. But who would have imagined that big rock would play a fellow such a trick? How in the world am I to get back again?"

From a great distance he could hear Darry shouting to him. He tried to answer his cousin, but whether or not his voice was heard he could not tell.

With his hands before him, he moved around, and scarcely had he taken a dozen steps when he slid down a rocky incline. Here there was water; and he shivered, thinking he might be dropping into an underground stream from which there would be no escape. But when a pool was gained it proved to be but several inches deep.

As Joe stood in the pool there came a sudden rumble of thunder to his ears. He listened, and by the sounds became convinced that an opening into the outer air could not be a great way off. Then came an unexpected flash of reflected light on the rocks by his side.

"Hurrah, that light came from outside!" he cried. "I'm not buried alive, after all. But I may be a good way from daylight yet."

He had some matches in his box, and lighting one of these he discovered a passageway below him, running off to his left. Further on he picked up a bit of dry wood and lit this. It made rather a poor torch, but proved better than nothing.

"Now to get out, and then to find my way back to where I left old Benson," was his mental resolve.

With extreme caution he stole forward to where the lightning revealed a distant opening. He did not leave one foothold until he was sure of the next, for he had no desire to experiment with another moving rock.

The thunder now reached his ears plainly, and the lightning at times made the front of the cave as bright as day.

"It's quite another place," was his thought. "That dangerous passage connects the two."

Suddenly, as Joe was advancing, he heard a clatter of horses' hoofs, and into the cave ahead rode three rough-looking men, all armed with rifles and pistols and each carrying small saddle-bags across his steed.

At first Joe thought to call out to the newcomers, but he checked himself, for their appearance was decidedly against them.

"I'll try to find out something about them first," he muttered. "Perhaps they belong to that gang of bad men Benson was telling us about yesterday." And then, as the three came to a halt in the center of the outer cave and dismounted, he crept closer, in the shadow of some sharp rocks, to overhear what they might have to say.

CHAPTER III
AN IMPORTANT CONVERSATION

"Who ever saw such a downpour before?" growled one of the three men, as he switched the water from his soft felt hat. "I'm wet to the skin."

"I'm no better off," replied one of the others. "I think we were fools to leave Macklin's place, Gilroy."

"Just what I think, Fetter," said the third man. "We could have waited as well as not."

"Yes, we could have waited, Potts," answered Matt Gilroy; "but, to tell the truth, I don't want to trust Macklin too far. He might play us foul."

"He wouldn't dare to do that," returned Gus Fetter.

"Why not – if he thought he would get a reward?" came from Nat Potts, the youngest of the trio. "One thing is certain, Macklin is crazy to make money."

"I know a thing or two of Macklin's past – that's why," went on Gus Fetter. "If he got us into trouble I wouldn't keep silent about him, and he knows it."

"Macklin is slippery, no two ways about it," said Matt Gilroy, as he took off his jacket and wrung the water out. "I am not inclined to trust him, and that is all there is to it."

"Did he ever belong to the old gang?" questioned Nat Potts. "Some say he did, and some say he didn't."

"He was a hanger-on, that's all," came from Matt Gilroy. "He was always afraid to take the chances of being shot, but was on hand when the spoils were divided. They used him as a messenger and a spy, but I don't believe he ever really helped to hold up a coach."

"Humph, then it's a wonder the old crowd had anything to do with him!"

"Oh, they had to have messengers and spies, and they never gave Macklin more than was coming to him, you can bet on that! I understand that when the Riverton coach was held up six years ago, and the gang got twenty-two thousand dollars, they gave Macklin five hundred, and he was glad to get that."

"That was a big haul!" cried Nat Potts enthusiastically. "I wish I had been in it."

"The gang was followed for two days – by the soldiers under Colonel Fairfield," went on Matt Gilroy, as he threw himself on the rocks, leaving his companions to start up a fire. "They had a hot time of it over to Bear Pass, I can tell you. Two men were shot, and one of them, Dan Hickey, my old chum, died from his wounds. They say Colonel Fairfield himself fired the shot that took poor Hickey in the head, and if that's so – well, I've got an account to square with the colonel, that's all."

"You can square that after we've had our little interview with the quartermaster," returned Gus Fetter with a hard laugh.

"That's right – we'll be sure to have the soldiers after us," put in Nat Potts. "They'll be doubly mad when they learn that the hold-up resulted in the emptying of the box with their wages."

"It will be a good haul if it goes through, boys. The quartermaster will be carrying not less than twelve thousand dollars of the government's money besides his other stuff," returned Matt Gilroy.

Here the conversation came to a temporary end, for Nat Potts had produced a black flask, from which each of the men took a deep draught. Then Potts and Fetter started in to build a roaring fire at which all might dry their clothing, leaving Gilroy, the leader of the crowd, to do as he pleased.

Joe had listened to the talk with mingled interest and horror. It did not take him long to realize the truth – that these men were thoroughly bad, and that they had been mixed up in road robberies of the past and were contemplating another robbery some time in the future.

"They mean to rob the quartermaster of the fort, when he is bringing in the soldiers' wages from Rockspur," he thought. "And that leader is going to shoot down the colonel if he can. Who would imagine men could be so bad! And that leader seems to be educated, too!"

Joe would have been very much surprised had he known the truth, which was that Matt Gilroy, often called The Shadow, was a college-bred man, having passed through one of the leading institutes of learning of the Pacific coast. But, following this college career, Gilroy had forged checks and committed a burglary, in company with an old chum named Hickey, and then the two had left Sacramento "between two days." Hickey had immediately joined the "knights of the road" and been shot down, as previously mentioned. Gilroy had drifted first to the Mississippi and then to Denver, and had not gone into the mountains until later. Now he was at the head of a desperate gang, numbering ten or a dozen, who had already committed several "hold-ups" of importance.

Soon the fire was burning brightly, and the three men took off part of their wearing apparel, that the articles might dry. They had brought some food with them, and as they sat eating and drinking they continued to discuss their plans. Nat Potts, who was not over nineteen or twenty, was evidently something of a new member, and asked many questions regarding the organization, and as he took in what was told him, so did Joe, listening with "all ears," as the saying goes.

"They must be as bad a crowd as can be found anywhere," thought the youth. "I wonder what they would do with me, if they found out I had been listening to their talk? Perhaps they'd kill me on the spot." And he gave a shiver.

The thunder and lightning had gradually abated, but with the coming of night the rain continued as steadily as ever. Fortunately for the desperadoes, however, the rocks sloped away from the entrance to the cave, so that no water came inside, while the fire made everybody quite comfortable.

Hardly knowing what to do, Joe continued behind the rocks, taking care to remain in the shadow. More than once he was afraid one or another of the men would start to investigate the surroundings and that he would be discovered.

"I wish they would go to sleep," he said to himself. "Then I might get a chance to slip past them and their horses."

With great impatience he watched the men finish up their supper, get out their pipes, and fall to smoking. In the meantime the horses had been led to the opposite side of the cave and fastened to the rocks.

As Joe waited for a chance to get away he wondered what Darry and old Benson were doing. More than likely they were looking for him. But were they in that other cave, at the narrow passageway, or did the old scout know of this second cave and the secret entrance to it?

"If Benson leads the way around to here there may be trouble," he mused. "It would be better if I could get out and head him off. But if I do get out, how shall I turn to find the trail we were pursuing? In this darkness a fellow couldn't see his hand before his face."

At last Fetter threw himself down on a blanket to rest, leaving Gilroy and Potts still conversing earnestly by the fire. The two desperadoes talked in a low tone, so that Joe now caught but little of what was said.

The backs of both men were turned toward the side of the cave where Joe was in hiding; and, plucking up courage, the youth started forward on tiptoe, bent upon getting out of the cave before the men should make some move which would expose him.

Step by step he advanced, until he reached a point where he was within a dozen feet of Gilroy and almost as close to Potts. He hardly dared to breathe, and his heart thumped madly beneath his jacket. But the men continued to smoke and talk, unconscious of his proximity.

At the entrance to the cave the rocks were somewhat rough and the mist had made them slippery. Joe was crawling forward rapidly, when one foot slipped, and he pitched headlong, making considerable noise.

"What was that?" cried Matt Gilroy, and leaped to his feet. He had been gazing into the fire, and for the moment could make out little in the darkness.

"I don't know," returned Nat Potts. "Something moving around out there, I think." And the younger man reached for his pistol, which still remained in his belt.

As rapidly as he could Joe sprang to his feet. A good bit of his wind had been knocked out of him, but he felt that he must not delay, and he ran for the outer air gasping for breath.

"Hi! stop!" roared Matt Gilroy, catching sight of him at last. "Stop, I tell you!"

"A boy!" ejaculated Nat Potts. "He must have been hiding in here!"

"If he was he overheard too much," growled Gilroy. "Come, we must catch him by all means," and he ran after Joe, with Potts following.