ILLUSTRATIONS

"Right off there! Look! Look!" The lanky cow puncher pointed out beyond the shadow of the solitary mesa . . . . . . Frontispiece

As it flared up, all three recoiled with expressions of dismay. At their very feet was a deep chasm.

A tempest of lead rattled about the engine. Almost before they realized it, they had swung around the curve.

CHAPTER I.

THE TRAIL OF THE HAUNTED MESA.

"Can you make out any sign of the mesa yet, Pete?"

The speaker, a sun-bronzed lad of about seventeen, mounted on a bright bay pony with a white-starred forehead, drew rein as he spoke. Shoving back his sombrero, he shielded his eyes from the shimmering desert glare with one hand and gazed intently off into the southwest.

"Nope; nary a speck, so fur. Queer, too; we ought to be seein' it by now."

Coyote Pete, as angular, rangy and sinewy as ever, gazed as intently in the same direction as the lad, Jack Merrill, himself. The pause allowed the remainder of the party to ride up. There was Ralph Stetson, a good deal browner and sturdier-looking than when we encountered him last in "The Border Boys on the Trail"; Walt Phelps, the ranch boy, whose blazing hair outrivaled the glowing sun; and the bony, grotesque form of Professor Wintergreen, preceptor of Latin and the kindred tongues at Stonefell College, and amateur archaeologist. Lest they might feel slighted, let us introduce also, One Spot, Two Spot and Three Spot, the pack burros.

"I always had an idea that the Haunted Mesa formed quite a prominent object in the landscape," put in Professor Wintergreen, referring to a small leather-bound book, which he had just taken from one of his saddle-bags.

"And I always had an idea," laughed Ralph Stetson, "that a landscape meant something with brooks and green trees and cows and—and things, in it."

The young son of "King Pin" Stetson, the Eastern Railroad King, looked about him at the gray desert, above which the sun blazed mercilessly down with all the intensity of a burning glass. Here and there were isolated clumps of rank-odored mesquite, the dreariest looking gray-green bush imaginable. The scanty specimens of this variety of the vegetable life of the desert were interspersed here and there by groups of scraggly, prickly cacti. Across such country as this, the party had been making its way for the past day and a half,—ever since, in fact, they had left behind them the foothills of the Hachetas, where, as we know, was located the ranch of Jack Merrill's father, and had entered the dry, almost untravelled solitudes of the Playas.

Jack Merrill consulted a compass that was strapped to his wrist.

"Well, we're keeping steadily in the right direction," he said. "Nothing for it but to keep on going; eh, Pete?"

"When yer cain't turn back, 'keep on goin's' a good word," assented the philosophical cow-puncher of the Agua Caliente, stroking his sun-bleached yellow moustache and untangling a knot in his pony's mane.

"It's up to us to get somewhere where there is water pretty quick," put in Walt Phelps; "the last time I hit the little drinking canteen I noticed that there wasn't an awful lot left in the others."

"No, and the stock's feelin' it, too," grunted Pete, digging his big, blunt-roweled spurs into his buckskin cayuse.

Followed by Jack on his Firewater, the professor on his queer, bony steed as angular as himself, Ralph on Petticoats—of exciting memory,—and Walt Phelps on his big gray, they pushed on.

The heat was blistering. In fact, to any one less accustomed to the arduous intensity of the sun's rays in this part of the country, it would have proved almost insupportable. But our party was pretty well seasoned by this time.

All of them wore the broad, leather-banded sombreros of the plainsmen except Professor Wintergreen, who had invested himself in a gigantic pith sun-helmet, from beneath which his spectacled countenance peered out, as Ralph said, "Like a toad peeking out from a mushroom." For the rest, the boys wore leather "chaps," blue shirts open at the neck, with loosely knotted red handkerchiefs about their throats. The latter were both to keep the sun off the back of their necks and to serve as protection for their mouths and nostrils against the dust in case of necessity,—as for example, when they struck a patch of burning, biting alkali. Of this pungent stuff, they had already encountered one or two stretches, and had been glad to muffle up the lower part of their faces as they rode through it.

As for Coyote Pete, those who have followed his earlier experiences are pretty familiar with that redoubtable cow-puncher's appearance; suffice it to say, therefore, that, as usual, he wore his battered leather "chaps," faded blue shirt, and his big sombrero with the silver stars affixed to the stamped leather band. In a holster he carried a rifle, as did the rest of the party, as well as his well-worn revolver. The others had provided themselves with similar weapons, although theirs glittered in blatant newness beside Pete's battered, but well-cleaned and oiled, "shootin' iron."

While they are pressing onward, with the Hachetas lying like a dim, blue cloud far behind them, let us tell the reader something about the quest that brings our party into the midst of this inhospitable place. As readers of "The Border Boys on the Trail" know, Professor Wintergreen had accompanied Jack Merrill and Ralph Stetson from Stonefell College, some weeks before, to spend a vacation on the Agua Caliente Ranch, belonging to Jack's father. The professor, as well as being on a vacation, was in a sense on a mission, for he bore with him the commission of a well-known institute of science in the East to investigate some of the mesas of this part of the world, and also to procure relics and trophies of the vanished race that once inhabited them, and accurate measurements of the strange formations.

Since their arrival at the ranch, some weeks before, events had so shaped themselves as to render the immediate undertaking of his mission impossible. The descent of Black Ramon de Barros on the ranch, as we have related, and the subsequent abduction of the boys to the old Mission across the border, had so fully occupied their attention, that all thought of the professor's errand had been lost sight of.

With Black Ramon, thanks to the boys, forever banished from his cattle-rustling raids, and the subsequent tranquility of routine life, had come a recollection of the professor's quest. Coyote Pete, a few days before this story opens, had volunteered to act as guide to the professor and his party to a mesa seldom visited except by wandering Indians and occasional cow-punchers. This was the Haunted Mesa, the location of which was so difficult to reach that previous relic-hunting expeditions had not included it in their travels.

Mr. Merrill was the more willing to allow the boys to go along, as he had been suddenly summoned into Chihuahua province, in Mexico, by reports of trouble at a mine—The Esmeralda—he owned there. Rumors of an insurrection had reached him—an insurrection which meant great peril to American interests. He had, therefore, lost no time in setting out to ascertain the true state of affairs at his mine, which, while a small one, was still likely to develop in time into an extremely valuable property.

Leaving the ranch in charge of Bud Wilson, he had started for the Mexican country without waiting for the departure of the professor's expedition. A short time later, "Professor Wintergreen's Haunted Mesans," as the boys insisted on calling themselves, had likewise started on their quest. With them, at Jack Merrill's invitation, went Walter Phelps, the son of a ranching neighbor of Mr. Merrill. Walt, it will be recalled, had shared the perils and adventures of the boys across the border, as related in the previous volume, and had been the instrument of piloting them out of the mysterious valley in which Black Ramon kept his plundered herds.

Mr. Merrill's last words had been ones of caution.

"Remember, boys, that if this trouble in Mexico attains real proportions, life and property along the border may be in great danger. In such a case, it will be your immediate duty to turn back."

"But, Dad," Jack had said, "you don't expect that plundering insurrectos would have the audacity to come northward into the Playas?"

Mr. Merrill laughed.

"I didn't say there was any danger even here, my boy. Least of all, out in that barren country. If there is an insurrection, it will doubtless be put down without any trouble, but it is always well to be prepared."

Like his brother ranchers along the border, Mr. Merrill at that time had no idea of the seriousness or extent of the insurrection. Had he had, he would, of course, have prohibited the party leaving the ranch. As it was, he, in common with his neighbors, deemed the insurrection simply one of those little outbreaks that occur every now and again in Mexico, and which hitherto had been promptly squashed by Diaz's army. And so, with no real misgivings, the party had bidden the bluff, good-natured rancher good-by, little dreaming under what circumstances they were to meet again.

But all this time we have been allowing our party to travel on without bestowing any attention upon them. As the afternoon wore on, Coyote Pete began to feel real apprehension about reaching their destination that evening. Walt Phelps' fear about the water had been verified. The supply was getting low. Provided they could "pick up" the mesa they were in search of before sundown, however, this was not so serious a matter as might have been supposed. Coyote Peter knew that there was a well at the mesa, the handiwork of the ancient desert-dwellers.

The really serious thing was, that although they had apparently been traveling in the right direction, they had not yet sighted it. The cow-puncher knew, though he did not tell his young companions so, that they should long since have spied its outlines. Of the real seriousness which their position might shortly assume, the boys had as yet, little idea. Coyote Pete was not the one to alarm them unless he was convinced it was really necessary.

Suddenly, Jack, who had been riding a little in advance of the rest, gave an exclamation and pointed upward at the sun.

"Say, what's the matter with the sun?" he exclaimed.

"Sun spots, I suppose," put in Ralph Stetson jokingly.

"I see what you mean," spoke up the professor; "it has turned quite red, and there seems to be a haze overcasting the sky."

"It's getting oppressive, too," put in Walt Phelps. "What's up, Pete?"

The cow-puncher had, indeed, for some time been noticing the same phenomenon which had just attracted their notice, but he had hesitated to draw their attention to it. Now, however, he spoke, and his voice sounded grave for one of Pete's usually lively temperament.

"It means that ole Mar'm Desert is gettin' inter a tantrum," he grunted, "and that we're in an almighty fix," he added to himself.

"Is it going to rain?" inquired Ralph Stetson, as it grew rapidly darker.

"Rain?" grunted Pete. "Son, it don't rain here enough to cover the back uv a dime, even if you collect all the water that fell in a year. No, siree, what's comin' is a heap worse than rain."

"An electric storm?" queried the professor.

"No, sir—a sand storm," rejoined the cow-puncher bluntly.

CHAPTER II.

THE SAND STORM.

As he spoke, a queer, moaning sort of sound, something like the low, distant bellow of a steer in pain, could be heard. The air seemed filled with it. Coming from no definite direction, it yet impregnated the atmosphere. The air, too, began noticeably to thicken, until the sun, from a pallid disc—a mere ghost of its former blazing self—was blotted out altogether. A hot wind sprang up and swept witheringly about the travelers.

"Ouch!" exclaimed Ralph Stetson suddenly. "Something stung me!"

"That's the sand, son," said Coyote Pete. "The wind's commencin' ter drive it."

"Is it going to get any worse?" inquired the professor anxiously.

"A whole lot, afore it gits any better," was the disconcerting reply.

"What'll we do, Pete?" asked Jack, turning to the cow-puncher.

It had now grown so dark that he could hardly see Pete's face. It was hot, too, with a heavy, suffocating sort of heat. The wind that drove the myriads upon myriads of tiny sand grains now darkening the air, was ardent as the blast from an opened oven-door.

"Get your saddles off, quick! Lie down, and put your heads under 'em," ordered the cow-puncher, briskly swinging himself out of his saddle as he spoke.

The others hastened to follow his example. It was not a minute too soon. Already their mouths were full of gritty particles, and their eyes smarted as if they had been seared with hot irons. The ponies could hardly be induced to stand up while the process of unsaddling was gone through. As for the burros, those intelligent beasts had thrown themselves down as soon as the halt was made. With their heads laid as low as possible, and their hind quarters turned to the direction of the hot blast, they were as well prepared to weather the sand storm as they could be.

The instant the saddles were off the ponies, down they flopped, too, in the same positions as their long-eared cousins. The bipeds of the party made haste to follow their animals' example, only, in their case, their heads were sheltered as snugly as if under a tent, by the big, high-peaked, broad-flapped Mexican saddles.

It was well they had made haste, for, as Pete had said, the sand storm was evidently going to get "a whole lot worse before it got better." The air grew almost as black as night, and the wind fairly screamed as it swept over them. Jack could feel little piles of sand drifting up about them, just as driven snow forms in drifts when it strikes an obstruction. How hot it was under the saddles! The boys' mouths felt as if they would crack, so dry and feverish had they become.

"Oh, for a drink of water!" thought Jack, trying in vain to moisten his mouth by moving his tongue about within it.

All at once, above the screaming of the wind, the lad caught another sound—the galloping of hoofs coming toward them at a rapid rate. For an instant the thought flashed across him that it was their own stock that had stampeded. He stuck his head out to see, braving the furious sweep of the stinging sand.

He withdrew it like a tortoise beneath its cover, with a cry that was only half of pain. Through the driving sand he had distinctly seen three enormous forms sweep by, seen like dim shadows in the gloom around. What could they have been? In vain Jack cudgeled his brains for a solution to the mystery.

The forms he had seen drift by had been larger than any horse. So vague had their outlines been in the semi-darkness, however, that beyond an impression of their great size, he had no more definite idea of the apparitions. That they were travelling at a tremendous pace was doubtless, for hardly had he sighted them before they vanished, and he could not have had his head out of its shelter for more than a second or so.

While the lad lay in the semi-suffocation of the saddle, his mind revolved the problem, but no explanation that he could think of would fit the case. "Might they not have been wild horses?" he thought.

But no,—these were three times the size of any horse he had ever seen. Besides, their blotty-looking outlines bore no semblance to the form of a horse.

But presently something happened which put the thought of the mysterious shadows out of his mind. The wind began to abate. To be sure, at first it hardly seemed to have diminished its force, but in the course of half an hour or so the party could once more emerge, like so many ostriches, from their sand-piles, and gaze about them.

Very little sand was in the air now, but it was everywhere else. In their eyes, mouths, ears, while, if they shook their heads, a perfect little shower of it fell all about them. The animals, too, struggling to their feet out of the little mounds that had formed around them, were covered with a thick coat of grayish dust. It was a sorry-looking party. With red-rimmed eyes, cracked, parched lips and swollen tongues, they looked as if they had been dragged through a blast furnace.

The sky above them now shone with its brilliant, metallic blue once more, while ahead, the sun was sinking lower. In a short time it would have set, and, as Ralph Stetson, in a choked voice, called for "Water," the same thought flashed across the minds of all of them simultaneously.

If they didn't get water pretty soon, their predicament promised to be a serious one.

An examination of the canteens showed that not much more than a gallon remained. If only they could yet "pick up" the mesa before dark, this would not be so serious a matter, but, situated as they were, it was about as bad as bad could be.

"Waal," said Pete, at length, stroking the last grains of sand out of his bleached moustache, "waal, I reckon we might as well hang fer a sheep as er lamb, anyhow. Ef we don't hit water purty soon, we'll be thirstier yet, so we might as well fill up now."

"Illogical, but sensible," pronounced the professor, leading an eager rush for the water canteens, which were carried on the pack burros.

"Here, hold on; that's enough!" cried Jack, as Ralph Stetson bent over backward with the canteen still at his lips.

"Why, I haven't begun to drink yet," protested Ralph.

"Chaw on a bullet, son," advised Pete. "Thet's highly recommended for the thirst."

"Water suits me better," grumbled Ralph, nevertheless yielding the canteen to Jack. The lad drank sparingly, as did Pete and the others. Ralph, alone, of all the party, appeared not to realize how very precious even the little water that remained might become before long.

Refreshed even by the small quantity they had swallowed of the tepid stuff, they remounted, and Pete clambered up upon his saddle. While his pony stood motionless beneath him, he stood erect upon the leather seat. From this elevation, he scanned the horizon on every side. Far off to the southwest was sweeping a dun-colored curtain—the departing sand-storm, but that was all. Otherwise, the desert was unchanged from its previous aspect.

"Let me hev a look at thet thar compass," said Pete, resuming a sitting posture once more.

Jack extended his wrist.

"The compass is all right, I know," he said confidently.

"And I know that we've bin hitting the right trail," declared Pete. "Last time I come this way was with an old prospector who knew this part of the country well enough to 'pick up' a clump of cactus. If that compass is right, we're headed straight."

"Yes—if," put in the professor. "But are you quite sure it is?"

This was putting the matter in a new light. Not one of the party was so ignorant as not to know that, in the many miles they had traveled, the deflection of the needle, by even the smallest degree, might have meant a disastrous error.

"Why, I—I—how can it help being right?" asked Jack, a little uncertainly.

"Which side have you been carrying your revolver on?" asked the professor.

"Why, you know—on the left side," rejoined Jack, with some surprise.

"And the compass on the left wrist?"

"Yes. Why? Isn't it——"

"No, it ain't!" roared Pete. "I see it all now, perfusser; that thar shootin' iron has bin deflectin' ther needle."

"I fear so," rejoined the professor.

Under his direction, Jack moved the compass into various positions, and at the end of a quarter of an hour they arrived at the startling conclusion that they had travelled perhaps many miles out of their way. The metal of the weapons Jack carried having, as they saw only too clearly now, deflected the needle.

"What an idiot I was not to think of such a possibility!" exclaimed Jack bitterly.

"Not at all, my boy," comforted the professor. "The same thing has happened to experienced sea-captains, and they have navigated many miles off their course before they discovered their error."