"Not many fellows would risk their lives for a dog," added Walter, with glowing eyes.

While the boys had been having such exciting times, Professor Zepplin also had been enjoying the delights of the mountains, as well as experiencing some of their more unpleasant features.

The lure of the yellow metal had gotten into the Professor's veins, immediately he had proved to his own satisfaction that that which Tad had discovered was real gold. The German could scarcely restrain his anxiety until the final return of Ben Tackers with the reply to the message he had sent on to Denver.

Ben had made the trip to Eagle Pass again on the third day, returning some time in the night, so that the Professor did not see him until the following day.

In the meantime, Professor Zepplin had not been idle. He had made frequent trips to the vicinity of the cave, bringing away with him each time a bagful of the ore, which he had detached with his hammer and chisel, all of which he had submitted to the blow-pipe, acid tests, and, in most instances, with the same result that had followed his first attempt.

The Professor's enthusiasm now was almost too great for his self-restraint. There could be no doubt of the correctness of his conclusions. There must be a rich vein of ore running through the rocks, terminating, he believed, in the cave itself.

Finally, urged on by this same enthusiasm, Professor Zepplin ventured in as far as the first chamber one afternoon, and what he found there raised his hopes to the highest pitch.

"I must be careful. I must be cautious. No one must know of my discovery just yet," he breathed, glancing apprehensively about, as he emerged from the cave on hands and knees.

Yet, as he came out, the Professor failed to observe two pairs of eyes that were watching his every movement from the rocks above the entrance to the cave.

Believing himself entirely alone, the Professor spread the ore he had just gathered on the ground before him, taking up each piece of mineral, fondling it and gazing upon it with glowing eyes.

"Gold! Bright yellow gold! A fortune, indeed!"

With a deep sigh of satisfaction, he gathered up the specimens, replacing them in his bag with great care. He drew the mouth of the bag shut, tying it securely.

So thoroughly absorbed was he with his great discovery, that he was all unconscious of the fact that a man had been creeping up to him from the rear while he had been thus engaged.

In one hand the fellow carried a stout stick, the free hand being employed to aid him in his cat-like creeping movements.

"I wonder if anyoue suspects," mused the scientist, sitting with a far-away look in his eyes. "Well, we shall see. We shall——"

The words died on the Professor's lips, as the tough stick, which had been raised above him, was brought down with a resounding whack, squarely on the top of his uncovered head.

Sudden darkness overwhelmed Professor Zepplin. He sank down with a moan, into utter oblivion.

When finally his heavy eyelids had struggled apart, night had fallen. At first, he could not imagine where he was nor what had happened. Shooting pains throbbed through his head and down into his arms and body.

The Professor uttered a suppressed moan, closed his eyes and lay back, vainly groping about in his disordered mind for a solution of the mystery.

Step by step he went back over the occurrences of the afternoon, which gradually became clearer, until at last he reached the point where he had finished his examination of the specimens of ore, in front of the cave entrance.

"And that's where I am now," decided Professor Zepplin, sitting up. "But, what happened then? I have it. Something hit me."

His hand instinctively went to his injured head. Then, with trembling fingers he began searching for the bag of minerals.

It was nowhere to be found. The Professor marveled at this for some minutes.

Like a blow, the answer came to him.

"Robbed!" he exclaimed.

Struggling to his feet, the German staggered down the rocks toward the camp, calling for Jose with the full strength of his voice. The Professor having been assisted to his tent and a lotion prepared for his aching head, Jose was hurried off to the cabin of Ben Tackers with an urgent demand for his presence.

When Ben responded, and had listened to the full account of Professor Zepplin's mishap, he sat grave and thoughtful.

"Bad lot," he growled. "Ab Durkin's one of the most lawless critters on the Park Range; and I've got all I'm goin' to stand from him. The sheriff will settle him when he gits here——"

"I don't care anything about the sheriff. The coward shall suffer for this, if he is the one who attacked me. I'll drive him out myself, if you won't help me. I'll——"

"I'm with you all right, pardner."

"Then, come. I'm ready now," urged the Professor rising.

"What you going to do?" "I am going back there to take possession of that claim. That's what I am going to do. And it will be worse for the man who tries to stop me," declared Professor Zepplin, taking a revolver from his kit, and examining it to see that all the chambers were loaded. "I'd like to see this man, Ab, attempt to interfere with my rights—I mean, interfere again."

Yet, had he known what was in store for him, the Professor might have hesitated before taking the step that he had determined upon.



CHAPTER XXIII

THE PONY RIDERS UNDER FIRE

With many a whoop and hurrah, the boys dashed into the home camp in the early forenoon of the following day.

Lige had left them three miles down the trail, that he might make a short cut to Eagle Pass for the purpose of getting word to the parents of the boys, that their trip had been concluded, and asking that directions for their further journeys might be sent to them at Denver, where they were to travel by easy stages.

The trail to camp being clear and easily followed, he felt no apprehension in allowing them to go on alone.

"Halloo the camp!" shouted Ned, hurling his sombrero on high, riding under and deftly catching it as it descended.

"Why, there's no one here!" exclaimed Tad Butler, looking about inquiringly, as they rode in.

Walter swung from his pony, and, hurrying to the tents, glanced into each in turn.

"That's queer. Looks as if no one had been here in a month. Well, suppose we unpack and wait."

"Somebody has been through these tents in a hurry," declared Tad after having made a hasty examination on his own account. "Did you notice that everything in the Professor's tent had been fairly turned inside out? There are our bows and arrows lying out there near where the camp fire was."

Now, the boys began to feel real concern.

"Tether the ponies and we will go out and see if we can find them," commanded Tad Butler.

"Shall we take our guns?" asked Stacy.

"Better not. Take your bows and arrows if you wish. We are going on the trail of two-footed game now, and we do not want to have guns. We might use them and be sorry for it afterwards."

Realizing the wisdom of his words, the boys laid aside their rifles, grabbed up their bows and quivers, and following Tad, who immediately struck off in the direction of the cave. Tad's own experience there was still fresh in memory.

At the entrance, they halted.

"Look at that! What do you think of that?" exclaimed Tad.

Above the entrance to the cave hung suspended a broad strip of sheeting. On it had been scrawled, evidently with a piece of blunt lead, the words:

THIS CLAIM BELONGS TO AB DURKIN. KEEP OFF!

The boys gazed at each other in amazement.

"We'll find out whom this claim belongs to!" declared Tad sternly. "I don't believe what that notice says at all. There is something more to this than we know about. Who'll go into the cave with me?"

"I will," chorused the boys.

"Follow me, then."

Tad moved forward, with the rest of the boys following closely behind him. But, as they started, a revolver shot rang out and a bullet sang by the head of Tad Butler.

"Back to the rocks!" shouted the boy, springing from the open place where they had been standing, at the same time urging his companions forward.

"What does this mean?" demanded Ned Rector.

"I don't know. We are in for trouble. Spread out and hide behind the boulders as well as you can, while we crawl back to camp. Chunky, you run for Ben Tackers as fast as your fat legs will carry you!"

With more order than might reasonably have been expected under the circumstances, the boys retreated rapidly, two more shots zipping over their heads as they leaped over a projecting ledge and scurried to cover without losing any time.

"I guess they're trying to scare us, that's all," decided Ned.

They could hear their unseen enemies, clambering down the rough ground that lay on either side of the cave, evidently bent on following them, now and then sending a bullet at one or the other of the dodging figures of the Pony Riders.

"Humph! Looks like it, doesn't it?" snapped Tad.

Suddenly rising to his full height, the boy waved his sombrero and hailed the men who bad been firing at them.

"Hold on, there! What are you trying to do? You're shooting at us! You had best look out what you are doing, unless you want to got into trouble yourselves. I——"

The answer came promptly.

A gun barked viciously, and the plucky lad's sombrero was snipped from his hand, with a bullet hole through its broad brim.

Tad ducked behind a rock with amazing quickness.

"Spread out a little more, fellows. It won't he so easy to hit us," he commanded. "Walter, you watch out on either side of us, while Ned and I take care of the front."

"Wish I had my rifle. I'd show them," growled Ned.

"I don't," snapped Tad. "We've got trouble enough as it is."

The boys had been carrying on their conversation in low tones, that they might not betray their positions to their enemies.

"Get out of there, you young cubs!" suddenly roared a voice, whose owner they could not see. "I'll l'arn ye to interfere with other folks' business. I'll give yer five minutes to shake ther dust of this hy'ar mounting off yer feet. If any of ye is here then, it'll be the worse for ye. This claim belongs to Ab Durkin. Now, mosey! D'ye hear?"

Tad Butler did hear. And now he saw as well as heard.

Ab, confident that he had nothing to fear from the boys, had taken his station on a large boulder, from which position he was giving his orders to the Pony Riders. Tad, peering from behind the rock where he had taken refuge, saw an evil face, topped by a weather-worn sombrero, and, beyoud it, the figures of four other men whose faces he was unable to make out.

"I say, will ye git?"

"No!" shouted Tad, his face flushing, as all the old fighting spirit in him came to the surface.

"Then, take the consequences!"

Ab Durkin raised his revolver, peering from rock to rock, not certain now as to the exact location of the boys. He seemed ready to fire the instant he made out the mark he was seeking.

Tad Butler never had been more cool in his life, and a strange sense of elation possessed him.

Motioning to the boys to lie low, Tad fitted an arrow to his bow, after which he waited a few seconds, keenly watching the enemy and measuring the distance to him, with critical eyes.

All at once the boy's right arm drew back. There followed a sharp twang.

"Ouch!"

The mountaineer leaped straight up into the air, which action was followed by two shots in quick succession, as both of the man's revolvers were accidentally discharged, the bullets burying themselves harmlessly in the ground in front of him.

Tad's arrow had sped home. Its blunt end had been driven with powerful force, straight against the left ear of Ab Durkin, having been deflected slightly from where Tad had intended to plant it.

"Lie low!" commanded the boy.

The next instant, a shower of revolver shots flattened themselves against the rocks all about the boys.

"Give them a volley and drop back quickly!" ordered Tad.

Three bows twanged, and yells of rage told the boys that at least some of their missiles had gone home. This was a different sort of warfare from anything to which these mountaineers had been accustomed, and, somehow, it had begun to get on their nerves, desperate men though they were.

"Follow me. We must change our positions again. They've got our range now," directed Tad, and the boys, wriggling along on their stomachs, to the left, dutifully followed their leader.

Tad was heading for a clump of sage brush, so that their operations might be the better masked. While he was doing so, the mountaineers, who also had taken to cover, were bombarding the rocks from which the Pony Riders had just made their escape.

>From their new position the boys were overjoyed to find that their enemies were in plain view.

"Take careful aim, and when I count three, let go at them. See that not one of you misses," directed the leader.

"Ready, now! One, two, three!"

Three bowstrings sang, and as many mountaineers, with yells of rage, began shooting, fanning every rock and bush about them, in hopes of driving from cover their tantalizing opponents.

At first they were at a loss to locate the boys' new position, but, after a little, as the arrows kept coming persistently from the sage bush, the mountaineers' bullets began to snip the leaves over the heads of the Pony Riders.

"Shoot slowly, and make every shot count!" directed Tad with stern emphasis.

Once, a bullet grazed Tad's left cheek, and Ned Rector narrowly missed death, escaping with the loss of a lock of hair. With rare generalship, Tad continually changed their positions, which tactics also were followed by the mountaineers, all the time crowding the boys nearer and nearer to their own camp.

Chunky had not yet returned, and Tad devoutly hoped that the boy would not be rash enough to attempt to do so now.

If anything, the boys thus far had the best of the battle, and although none had sustained a serious wound, every one of the mountaineers had marks on his body to show where blunt tipped arrows, driven by a strong arm, had been stopped.

Now, a new danger menaced the brave little band. Their quivers were nearly empty. Tad, discovering it, drew his hunting knife from its sheath, tossing it to Walter Perkins.

"Quick! Cut some sticks and make some arrows. Don't lose a second. Make them as straight as possible, or we shall be unable to hit a thing."

By the time their supply had become almost exhausted, Walter had succeeded in turning out more than half a dozen new arrows. Yet no sooner had they begun driving these at their enemies than the mountaineers sent up a yell of defiance. They recognized the predicament the boys were in.

"Cease firing!" commanded Tad, realizing at once that their enemies had discovered their plight.

"Fellows, we are about at the end of our rope. Give me the arrows. Then, you two make your get-away. But be careful not to expose your bodies to the fire of those brutes. When you get far enough away run for Ben Tackers' cabin. You can hide there, anyway," directed Tad Butler.

"Yes, but what are you going to do? You surely don't intend to remain here?" protested Walter.

"I'm going to cover your retreat. They'll think we have no more ammunition left and then they'll start to rush us. That's the time I'll surprise them. We have a few arrows left. They won't be so fast to——"

"See here, Tad Butler, what do you take us for?" demanded Walter, his eyes snapping. "Do you think we are going to desert you and leave you here, perhaps to he killed?"

"While we run away?" added Ned. "I guess not. What breed of tenderfoot do you think we belong to?"

"No! We stay with you," announced Walter firmly.

"Oh, very well. I'm sorry. Hold your arrows till you have to shoot, but it would he much better for you to go while you have a chance."

Recognizing the helplessness of the boys, the mountaineers began moving on their position, revolver shots occasionally zipping against the rocks. It was almost impossible for the boys to return the fire with their few remaining arrows, for fear of exposing themselves to too great danger.

"I guess it's about up with us," said Tad, coolly stringing his last arrow.



CHAPTER XXIV

CONCLUSION

The faces of the three boys were pale, though a half smile played about the lips of Tad Butler. "Lie down!" he said.

Tad was watching the enemy from behind a rock, nervously fingering the arrow that lay across his bow.

At last the men had approached to within three or four rods of them. Tad rose, not a muscle of his body appearing to quiver when they sent a few shots at him.

Deliberately drawing back his bowstring, the boy drove one of the heavy missiles that Walter had cut for him full into the evil face of Ab Durkin. They could hear the impact as the heavy stick landed.

Ab toppled over backwards with a yell of rage.

"That's our last shot." Tad threw down his bow, standing with folded arms calmly facing the enemy. "Hands up!" rang the stern command. At first, Tad thought the order was directed at himself. Then a puzzling expression settled over his face as he saw the mountaineers suddenly wheel, then throw their hands above their heads.

Lige Thomas, on his way to the Pass, had not gone far before he came up with the sheriff, to whom he explained what he had heard about the doings of Ab Durkin and his gang. While they were conversing, the sound of the shooting was borne faintly to them on the clear mountain air.

Suspecting something of the truth, Lige had wheeled his horse and ridden back with all speed, followed by the sheriff and his little posse. They had arrived at the moment when they were, perhaps, needed most.

Creeping down into an advantageous position, they had put a quick and sudden end to the onslaught of the mountaineers, who were in no mood for trifling with their young opponents now.

In a few moments the sheriff had each of the five men in handcuffs, and without having had to fire a shot. Tad, who had rushed out, followed by his companions, explained to the posse that the Professor and Jose were missing. He believed now that they were prisoners in the cave.

And there they found them—Professor Zepplin, Ben Tackers and Jose, bound hand and foot.

All of them bad been taken captive by the mountaineers when they visited the cave the night before.

Ab Durkin was fuming with rage.

"These cayuses was stealin' my claim," he snarled. "Understand me, they was stealin' the gold, and, when I tried to drive them off, they sailed into us——"

"Yes, I observed that you were shooting at three boys," retorted the sheriff, sarcastically.

"See, thar's my mark over that hole in the ground," continued Ab pointing to the sign that was flapping idly in the breeze. "That's my claim and no man ain't goin' ter take it away from me, neither."

"My friend," retorted Professor Zepplin, stepping forward frowning. "If I did what you deserve, I should send a bullet into your miserable carcass. Instead I'm going to tell you about a little paper I have here."

All eyes instantly were centered on the Professor.

"This little document, gentlemen, is a certificate from the register's office at Denver, stating that the Lost Claim, which lies just within this cave here, is the property of Herman von Zepplin. Had you examined this neighborhood more closely you would have found my claim stakes driven, as required by law. With the certificate is a report on the assay of the samples of ore I sent them, showing that, while the mine is a valuable property, it does not contain such untold wealth as generally has been believed. However, it may give these boys a few thousands apiece."

"The Lost Claim! Is it possible?" breathed the boys.

"Yes, Ben Tackers will tell you I am not mistaken. He has known this all along. I had the mine registered in my own name as this was the quickest way to secure it. However, Tad Butler is the rightful owner. Immediately upon our arrival at Denver, I shall take legal measures to transfer the property to him," announced the Professor. Tad slowly shook his head. "It's not mine alone," he answered, gazing at his companions, all of whom, now, were flushed with suppressed excitement. "The Lost Claim belongs to the Pony Rider Boys Club, of which Professor Zepplin is now a member and therefore entitled to share equally with us. Are you willing, fellows?"

"Yes!" they shouted, following it with three cheers and a tiger for Professor Herman von Zepplin.

"As for my share in the claim, Professor, I would prefer that you made it over to my mother," said Tad, with a glad smile. "That is, if no one in the club objects," he added.

"Well, I guess not," replied Ned, with strong emphasis.

Later in the day, the sheriff and his party set out for Eagle Pass with the prisoners. Each member of the gang was sentenced to a term in prison because of the attack on the Pony Rider Boys.

That same day the boys began their preparations for leaving the mountains. At Denver, where they arrived within a week, they effected a sale of the Lost Claim, with the permission of their parents, most of whom came on to fulfill the necessary legal requirements, and when the transfer of the mine had been made, the Pony Rider Boys were twenty-five thousand dollars richer, giving them exactly five thousand dollars apiece. Tad's share was promptly turned over to his mother. Though he did not know it, the money was deposited to his credit in Mr. Perkins's bank.

The exciting experiences of the Pony Rider Boys were not yet at an end. The boys will be heard from again in another volume under the title: "THE PONY RIDER BOYS IN TEXAS; Or, The Veiled Riddle of the Plains." In this forthcoming volume the narrative of how the boys learned to become young plainsmen, and the stirring account of their experiences in the great cattle drive, will be found full of fascination and in every detail true to the strenuous out-door life described.

THE END.