The discovery galvanized Stratton into instant, alert attention. Motor-cars were rare in this remote range country and confined almost solely to the sort of "flivver" which is not entirely dependent on roads. The presence in the north pasture of this powerful gray machine, which certainly did not belong in the neighborhood, was more than significant, and Buck tried at once to get a view of the occupants.

In this he was not successful. There were three of them, one in the driver's seat and two others in the tonneau. But the top prevented more than a glimpse of the latter, while the cap and goggles of the chauffeur left visible only a wedge of brick-red, dust-coated skin, a thin, prominent nose and a wisp of wiry black mustache.

One thing was certain--the fellow knew his job. Under his masterly guidance the big car plowed steadily through the clogging sand, avoiding obstructions or surmounting them with the least possible expenditure of power, never once stalled, and, except for a necessary slight divergence now and then, held closely to its northwesterly course across the desert.

Buck, who had driven under the worst possible battle-front conditions, fully appreciated the coaxing, the general manoeuvering, the constant delicate manipulation of brake and throttle necessary to produce this result. But his admiration of the fellow's skill was swiftly swallowed up in eager curiosity and speculation.

Who were they? What were they doing here? Where were they going? At first he had a momentary fear lest they should see him perched up here on his point of vantage. Then he realized that the backing of rocks prevented his figure from showing against the skyline, which, together with the distance and the clouds of dust stirred up by the car itself, made the danger almost negligible. So he merely dismounted and, leaning against his horse, kept the glasses riveted on the slowly moving machine.

The car advanced steadily until it reached a point about a quarter of a mile from the rough ground and a little distance north of where Buck stood. Then it stopped, and a capped and goggled head was thrust out of the tonneau. Buck could make out nothing definite about the face save that it was smooth-shaven and rather heavy-jowled. He was hoping that the fellow would alight from the car and show himself more plainly but to his disappointment the head was presently drawn back and the machine crept on, swerving a little so that it headed almost due north.

Ten minutes later it halted again, and this time the two men got out and walked slowly over the sand. Both were clad in long dust-coats, and one seemed stouter and heavier than the other. Unfortunately they were too far beyond the carrying power of the binoculars to get anything more clearly, and Buck swore and fretted and strained his eyes in vain. After a delay of nearly an hour, he saw the car start again, and followed its blurred image until it finally disappeared beyond an out-thrust spur well to the northward.

Stratton lowered his glasses and stood for a moment or two rubbing his cramped arm absently. His face was thoughtful, with a glint of excitement in his eyes. Presently his shoulders straightened resolutely.

"Anyhow, I can follow the tracks of the tires and find out what they've been up to," he muttered.

The difficulty was to descend from his rocky perch, and it proved to be no small one. He might have clambered down the face of the cliff, but that would mean abandoning his horse. In the end he was forced to retrace his steps along the twisting ledge by which he had come.

From his knowledge of the country to the south, Buck had started out with the idea that it would be simple enough to reach the flats through one of the many gullies and cañons that fringed the margin of the hills further down. He had not counted on the fact that as the range widened it split into two distinct ridges, steep and declivitous on the outer edges, with the space between them broken up into a network of water-worn gullies and arroyos.

"I ought to have known from the look of the north pasture that all the water goes the other way," he grumbled. "Best thing I can do is to head for that trail Bud spoke of that cuts through to the T-T ranch. It can't be so very far north."

It wasn't, as the crow flies, but Buck was no aviator. He was forced to take a most tortuous, roundabout route, and when he finally emerged on the first passable track heading approximately in the right direction, the sun was low and there seemed little chance of his accomplishing his purpose in the few hours of daylight remaining.

Still, he kept on. At least he was mapping out a route which would be easily and swiftly followed another time. And if darkness threatened, he could return to his little camp through the open Shoe-Bar pastures, where neither Lynch nor his men were at all likely to linger after dusk.

The trail followed a natural break in the hills and, though not especially difficult under foot, was twisting and irregular, full of sharp descents and equally steep upward slopes. Buck had covered about two miles and was growing impatient when he came to the hardest climb he had yet encountered and swung himself out of the saddle.

"No use killing you, Pete, to save a little time," he commented, giving the horse's sweaty neck a slap. "I'd like to know how the devil those two ever drove a steer through here."

It did seem as if this must have been uncommonly difficult. The trail curved steeply around the side of a hill, following a ledge similar to the one Buck had taken earlier in the afternoon with such interesting results. There was width enough for safety, but on one side the rocks rose sharply to the summit of the hill, while on the other there was a sheer drop into a gulch below, which, at the crown of the slope, must have been fifty or sixty feet at least.

Leading the horse, Buck plodded on in a rather discouraged fashion until he had covered about three-quarters of the distance to the top. Then of a sudden his pace quickened, as a bend in the trail revealed hopeful glimpses of open spaces ahead. It was nothing really definite--merely a falling away of the hills on either side and a wide expanse of unobstructed sky beyond, but it made him feel that he was at last coming out of this rocky wilderness. A moment or two later he gained the summit of the slope and his eyes brightened as they rested on the section of sandy, cactus-dotted country spread out below him.

A dozen feet ahead the trail curved sharply around a rocky buttress, which hid the remainder of it from view. In his eagerness to see what lay beyond, Stratton did not mount but led his horse over the short stretch of level rock. But as he turned the corner, he caught his breath and jerked back on Pete's reins.

By one of those freaks of nature that are often so surprising, the trail led straight down to level ground with almost the regularity of some work of engineering. At the foot of it stood the gray motor-car--empty!

The sight of it, and especially that unnatural air of complete desertion, instantly aroused in Buck a sense of acute danger. He turned swiftly to retreat, and caught a glimpse of a figure crouching in a little rocky niche almost at his elbow.

There was no time to leap back or forward; no time even to stir. Already the man's arm was lifted, and though Stratton's hand jerked automatically to his gun, he was too late.

An instant later something struck his head with crushing force and crumpled him to the ground.

When Buck began to struggle out of that black, bottomless abyss of complete oblivion, he thought at first--as soon as he could think at all--that he was lying in his bunk back at the Shoe-Bar. What gave him the idea he could not tell. His head throbbed painfully, and his brain seemed to swim in a vague, uncertain mist. A deadly lassitude gripped him, making all movement, even to the lifting of his eyelids, an exertion too great to be considered.

But presently, when his brain had cleared a little, he became aware of voices. One in particular seemed, even in his dreamlike state, to sting into his consciousness with a peculiar, bitter instinct of hatred. When at length he realized that it was the voice of Tex Lynch, the discovery had a curiously reviving effect upon his dazed senses. He could not yet remember what had happened, but intuitively he associated his helplessness with the foreman's presence, and that same instinct caused him to make a desperate attempt to understand what the man was saying. At first the fellow's words seemed blurred and broken, but little by little their meaning grew clearer to the injured man.

"... ain't safe ... suspects somethin' ... snoopin' around ever since ... thought he was up to somethin' ... saw him up on that ledge watchin' yuh ... dead sure. I had a notion he'd ride around to this trail, 'cause it's the only way down to north pasture. I tell yuh, Paul, he's wise, an' he'll spill the beans sure. We got to do it."

"I don't like it, I tell you!" protested a shrill, high-pitched voice querulously. "I can't stand blood."

"Wal, all yuh got to do is go back to the car an' wait," retorted Lynch. "I ain't so partic'lar. Besides," his tone changed subtly, "his head's smashed in an' he's sure to croak, anyhow. It would be an act of kindness, yuh might say."

"I don't like it," came again in the shrill voice. "I'd--hear the shot. I'd know what you were doing. It would be on my--my conscience. I'd dream-- If he's going to--to die, as you say, why not just--leave him here?"

An involuntary shudder passed over Stratton. It had all come back, and with a thrill of horror he realized that they were talking about him. They were discussing his fate as calmly and callously as if he had been a steer with a broken leg. A feeble protest trembled on his lips, but was choked back unuttered. He knew how futile any protest would be with Tex Lynch.

"Yeah!" the latter snarled. "An' have somebody come along an' find him! Like as not he'd hang on long enough to blab all he knows, an' then where would we be? Where would we be even if somebody run acrost his body? I ain't takin' no chances like that, I'll tell the world!"

"But isn't there some other way?" faltered the high-pitched voice.

In the brief pause that followed, Stratton dragged his lids open. He was lying where he had fallen at the curve in the trail. Tex Lynch stood close beside him. A little beyond, leaning against the rocky cliff, was a bulky figure in a long dust-coat. He had pushed up his motor-goggles and was wiping his forehead with a limp handkerchief. His round, fat face, with pursed-up lips and wide-open light-blue eyes, bore the expression of a fretful child. On his left was a lean, thin-faced fellow with a black mustache who looked scared and nervous. There was no sign of the third person who had been in the car, and even at this crucial moment Buck found time to observe the absence of his horse, Pete, and wondered momentarily what had become of him.

"Yuh an' Hurd go back to the car." Lynch broke the silence in a tone of sudden decision. "I'll tend to this business, an' there won't be no shootin' neither. Hustle, now! We ain't got any time to lose."

Again Buck shuddered, and there pulsed through him that tremendous and passionate instinct for self-preservation which comes to every man at such a time. What Tex meant to do he could not guess, but he knew that if he were left alone with the fellow he might as well give up all hope. He was weak as a cat, and felt sure that no appeal from him would move Lynch a particle. His only chance lay with the fat man and his companion, and as the two turned away, Buck tried his best to call out after them.

The only result was an inarticulate croak. Lynch heard it, and instantly dropping on his knees, he clapped one hand over Stratton's mouth. In spite of Buck's futile struggles, he held it there firmly while the two men moved out of sight down the trail. His face, which still bore the fading marks of Buck's fists, was a trifle pale, but hard and determined, and in his eyes triumph and a curious, nervous shrinking struggled for mastery.

But as the moments dragged on leaden wings, not a word passed his tight lips. Presently he glanced swiftly over one shoulder. An instant later Buck's lips were freed, and he felt the foreman's hands slipping under his body.

"You hellion!" he gasped, as Lynch's purpose flashed on him in all its horror. "You damned cowardly hound!"

As he felt himself thrust helplessly toward the precipice, Buck made a tremendous, despairing effort and managed to catch Lynch by the belt and clung there for a moment. When one hand was torn loose, he even struck Tex wildly in the face. But there was no strength in his arm, and Lynch, with a growl of rage, jerked himself free and sprang to his feet.

For an instant he towered over his helpless enemy, white-faced and hesitating. Then Stratton caught the hard impact of his boot against his side, and felt the edge of the rock slipping horribly beneath him. Powerless to help himself, his clutching fingers slid despairingly across the smooth surface. A blinding ray of sunlight dazzled him for an instant and vanished; the mountain trail flashed out of sight. His heart leaped, then sank, with a tremendous, poignant agony that seemed to tear him into shreds. Then blackness seemed to rush out of the gulch to enfold him in an impenetrable cloud of merciful oblivion.