A sudden bright flash lighted up the camp, throwing the little white tents into hold relief against the sombre background of the mountains. It was followed after an interval by a low rumble of distant thunder that buffeted itself from peak to peak of the Rockies.
The Pony Riders stirred restlessly on their cots and tucked the blankets up under their chins.
Close upon the first report followed another and louder one, that sent a distinct tremor through the mountain.
"What's that?" whispered Stacy Brown, reaching from his cot and grasping Tad Butler by the shoulder.
"A mountain storm coming up," answered the boy, who for some time had lain wide awake listening to the ever increasing roar. "Go to sleep."
Yet, instead of following his own advice, Tad lay with wide-open eyes awaiting the moment when the storm should descend upon their camp in full force.
He had not long to wait.
With a crash and a roar, as if the batteries of an army had been suddenly let loose upon them, the elements opened their bombardment directly over the camp.
"Ugh!" exclaimed Chunky in a muffled voice, as he crawled further down under the blanket to shut out the glare of the lightning.
For a few moments the boys lay thus. Then Tad, rising, slipped to the opening of the tent and looked out wonderingly upon the impressive scene. Each flash appeared to light up the mountains for miles around, their crests lying dark and forbidding, piled tier upon tier, the blue, menacing flashes hovering about them momentarily, then fading away in the impenetrable darkness.
The camp appeared to be wrapped in sleep, and, by the bright flashes, Tad observed that the burros of the pack train were stretched out sound asleep, while, off in the bushes, he could hear the restless moving about of the ponies, their slumbers already disturbed by the coming of the storm.
The Pony Riders had been out three days from Pueblo, to which point they had journeyed by train, the stock having been shipped there in a stable car attached to the same train. In the city of Pueblo they found that all preparations for the journey had been made by Lige Thomas, the mountain guide whom Mr. Perkins had engaged to accompany them.
Besides the four ponies of the boys there were the Professor's cob, Thomas's pony and a pack train consisting of six burros, the latter in charge of Jose, a half-breed Mexican, who was to cook for the party during their stay in the mountains.
It was a brave and joyous band that had set out from the Colorado city in khaki trousers, blue shirts and broad-brimmed sombreros for an outing over the wildest of the Rocky Mountain ranges.
By this time the boys had learned to pitch and strike camp in the briefest possible time--in short, to take very good care of themselves under most of the varying conditions which such a life as they were leading entailed.
They had made camp this night on a rooky promontory, under clear skies and with bright promise for the morrow.
Tad gave a quick start as a flash of lightning disclosed something moving on the far side of the camp.
"What's that!" he breathed.
With quick intuition, the boy stepped back behind the flap of the tent, and, peering out, waited for the next flash with eyes fixed upon the spot where he thought he had observed something that did not belong there.
"Humph! I must be imagining things tonight," he muttered, when, after three or four illuminations, he had discovered nothing further.
Tad was about to return to his cot when his attention was once more attracted to the spot. And what he saw this time thrilled him through and through.
A man was cautiously leading two of the ponies from camp, just back of Professor Zepplin's tent.
The boy paused with one hand raised above his head, prepared to pull the tent flap quickly back in place in case the stranger chanced to glance that way, all the while gazing at the man with unbelieving eyes.
Was he dreaming? Tad wondered, pinching himself to make sure that he really was awake.
Once more, impenetrable darkness settled over the scene, and, when the next flash came the camp had resumed its former appearance.
Tad Butler hesitated only for the briefest instant.
"Ahoy, the camp!" he shouted at the top of his voice, springing out into the open. "Wake up! Wake up!"
As if to accentuate his alarm, a twisting gust of wind swooped down upon the white village. Accompanied by the sound of breaking ropes and ripping canvas, the tent that had covered Professor Zepplin was wrenched loose. It shot up into the air, disappearing over a cliff.
Now the lightning flashes were incessant, and the thunder had become one continuous, deafening roar.
Stoical as he was, the Professor, thus rudely awakened, uttered a yell and leaped from his cot, while the boys of the party came tumbling from their blankets, rubbing their eyes and demanding in confused shouts to know what the row was about.
But Lige, experienced mountaineer that he was, instinctively divined the cause of the uproar, when, emerging from his tent, he saw Tad darting at top speed across the camp ground.
"The ponies! The ponies!" shouted the boy, as he disappeared in the bushes, regardless of the fact that he was clad only in his pajamas, and that the sharp rocks were cutting into his bare feet like keen-edged blades.
"What about the ponies?" roared Ned Rector, quickly collecting his wits and following in the wake of the fleeing Tad.
"Stolen! Two of them gone!" was the startling announcement thrown back to them by the freckle-faced boy.
By this time the entire camp, with the exception of Professor Zepplin and Stacy Brown, had set out on a swift run, following on the trail of Tad.
Ahead of him, the boy could hear the ponies' hoofs on the rocks, and now and then a distant crash told him they were working up into the dense second growth that he had seen in his brief tour of inspection earlier in the evening. He realized from the sound that he was slowly gaining on the missing animals.
Tad's blood was up. His firm jaw assumed the set look that it had shown when he won the championship wrestling match at the high school.
The shouts of the others at his rear, warning him of the danger and calling upon him to return, fell upon unheeding ears. So intent was the boy upon the accomplishment of his purpose that he gave no heed to the fact that the sounds ahead had ceased, and that only the soft patter of his own feet on the rocks broke the stillness between the loud claps of thunder.
Yet, even if Tad had sensed this, its meaning doubtless would have been lost upon him, unused as he was to the methods of mountaineers. So the boy ran blindly on in brave pursuit of the man who had stolen their mounts while the Pony Riders slept.
Suddenly, without the slightest warning, Tad felt himself encircled by a pair of powerful arms, and, at the same time, he was lifted clear of the ground.
But even then the lad's presence of mind did not desert him, though the vise-like pressure about his body made him gasp.
All his faculties were instantly on the alert. But he realized now that his only hope lay in attracting the attention of the others of his party, who could be only a short distance away, for he could still hear their shouts.
"Help!"
Tad's shrill voice punctuated a momentary lull in the storm.
"Coming!" answered the voice of the guide, its strident tones carrying clearly to Tad, filling him with a feeling as near akin to joy as was possible under the circumstances.
With a snarl of rage the boy's captor suddenly released his hold around the waist and grasped Tad quickly by the knees. So skilfully had the move been executed that Tad Butler found himself dangling, head down, before he really understood what had occurred. His head was whirling dizzily. He felt his body swaying from side to side, his head describing an arc of a circle, as he was rapidly being swung to and fro.
"Where are you, Tad?"
"Here!" came the muffled voice of the boy, too low for the others to catch.
Tad knew that they would have to hurry if they were to save him, for as soon as the dizzy swinging of his body began he had understood the purpose of his captor. At any second the boy might find himself flying through space-- perhaps over a precipice. It plainly was the intent of the man to hurl the boy far from him, as soon as Tad's body should have attained sufficient momentum to carry it.
However, before the fellow was able to put his desperate plan fully into execution, Tad, with the resourcefulness of a born wrestler, suddenly formed a plan of his own.
As his body swung by that of his captor, the boy threw out his hands, clasping them about the left leg of the other and instantly locking his fingers.
It seemed as if the jolt would wrench his arms from their sockets. Yet Tad held on desperately. And the result, though wholly unexpected by the mountaineer, was not entirely so to Tad. He had figured--had hoped--that a certain thing might occur. And it did.
The man's left leg was jerked free of the ground, and before he was able to catch his balance the fellow fell heavily on his side. Tad, with keen satisfaction, heard him utter a grunt as he struck. But before the boy could release himself he was grabbed and pulled up over his adversary by the latter's left hand, his right still being pinioned under his own body. Yet the mountaineer's move had not been entirely without results favorable to his captive.
"I'll kill you for this!" snarled the man, fuming with rage.
Tad, groping for a wrestler's hold, felt his hand close over the hilt of a knife in the man's belt. And, as the boy was hauled upward, the blade came away from its sheath, clasped in Tad's firm grip.
But not even with this deadly weapon in hand did Tad Butler for a second forget himself. He flung the knife as far from him as his partly pinioned arms would permit, and, with keen satisfaction, heard it clatter on the rocks several feet away.
"You'll do it without that cowardly weapon, then!" gasped the boy.
Though thoroughly at home in a wrestling game, Tad knew that he would he no match for the superior strength of his antagonist. So, resorting to every wrestling trick that he knew, he sought to prevent the fellow from getting the right arm free. However, the most the lad could hope to accomplish would be to delay the dreaded climax for a minute or more.
With an angry, menacing growl, the mountaineer threw himself on his hack, hoping thereby to free the pinioned arm.
"Now, I've got you, you young cub!"
Instantly, both of Tad's knees were drawn up and forced down with all his strength on his adversary's stomach. From the growl of rage that followed, Tad had the satisfaction of knowing that his tactics had not been without effect.
"You--you only think you have," retorted the boy, breathing heavily under the terrible strain.
The mountaineer might now have hurled the boy from him. To do this, however, would have been giving Tad an opportunity to escape, of which he would have been quick to take advantage; and so, gulping quick, short breaths, and struggling with his slightly built adversary, Tad's captor finally managed to throw the lad over on his back.
So heavily did Tad strike that, for the moment, the breath was fairly knocked from his body.
Recovering himself with an effort, he raised a piercing call for help.
All grew black about him. He no longer saw the brilliant flashes of lightning that at intervals lighted up the scene, nor heard the voices of his companions frantically calling upon him to come back. The mountaineer's sinewy fingers had closed in an iron-grip over Tad Butler's throat.