He straightened suddenly and drew back his arm. The Desert Rat saw that he was about to hurl a large smooth stone, and simultaneously he dodged and reached for his gun. But he was a fifth of a second too slow.

The stone struck him on the side of the head, rather high up, and he collapsed into a b.l.o.o.d.y heap.

On the instant the footsore man from Boston developed an alacrity and definiteness of purpose that would have surprised the Desert Rat, had he been in condition to observe it. He seized the gad which the mozo had dropped, climbed upon the lightest laden burro and, driving the others before him, set off for Chuckwalla Tanks. The Indian had disappeared by this time, and there was little danger of overtaking him; so with the two low hills as his objective point, the Easterner circled a mile out of the direct course which he knew the Indian would take, and when the dawn commenced to show in the east he herded the pack-animals down into a swale between two sand-dunes. With remarkable cunning he decided to scout the territory before proceeding further; hence, as soon as there was light enough to permit of a good view, he climbed to the crest of a high dune and looked out over the desert. As far as he could see no living thing moved; so he drove the pack train out of the swale and headed for the gorge between the hills. The thirsty burros broke into a run, hee-hawing with joy as they sniffed the water, and within a few minutes man and beasts were drinking in common at Chuckwalla Tanks.

The man permitted them to drink their fill, after which they fell to grazing on the short gra.s.s which grew in the draw. While he realized the necessity for haste if he was to succeed in levanting with the gold, the tenderfoot had been too long a slave to his creature comforts to face another day without breakfast. He abstracted some grub from one of the packs and stayed the pangs of hunger. Then he bathed his blistered feet, filled the water kegs, rounded up his pack train and departed up the draw. After traveling a mile the draw broadened out into the desert, and the man from Boston turned south and headed for the Rio Colorado. He was walking now and appeared to have forgotten about his blistered heel, for at times he broke into a run, beating the burros, screaming curses at them with all the venom of his wolfish soul, for he was pursued now by the fragments of his conscience. His attack upon the Desert Rat had been the outgrowth of a sudden murderous impulse, actuated fully as much by his hatred and fear of the man as by his desire to possess the gold. One moment he would shudder at the thought that he had committed murder; the next he was appalled at the thought that after all he had only stunned the man--that even now the Desert Rat and his Indian retainer were tracking him through the waste, bent on wreaking summary vengeance.

He need not have worried so prematurely. A low range of black malpais b.u.t.tes stretched between him and the man he had despoiled, and as yet the direction of his flight could not be observed. He drifted rapidly south and presently disappeared into one of those long swales which slope gradually to the river.

Here, weaving his way among the ironwood that grow thickly in this section of the desert, for the first time since the commission of his crime he felt safe.

CHAPTER II

It was still dark when the Desert Rat regained consciousness. He lay for quite a while thereafter, turning things over in his befuddled brain, striving to gather together the tangled thread of the events of the night. Eventually he succeeded in driving his faculties into line. He rolled over, got to his hands and knees and paused a minute to get a fresh grip on himself. His aching head hung low, like that of a dying horse; in the silence of the night he could hear the drip, drip of his blood into the sand.

Presently he began to move. Round and round in the sage he crawled, like some weary wounded animal, breaking off the rotten dead limbs which, lie close to the base of the shrub. Three piles of sage he gathered, placing the piles in a row twenty feet apart. Then he set fire to them and watched them burst into flame.

It was the desert call for help: three fires in a row by night, three columns of smoke against the horizon by day--and the Cahuilla Indian, coming down the draw from Chuckwalla Tanks five miles away, saw flaming against the dawn this appeal of the white man he loved, for whom he lived and labored. Straight across the desert he ran, with the long tireless stride that was the heritage of his people. His large heavy shoes r.e.t.a.r.ded him; he removed them, tucked them under his arm and with a lofty disdain of tarantulas and side-winders fled barefooted.

Three-quarters of an hour from the time he had first seen the signal-fires, the mozo was kneeling beside the stricken Desert Rat, who lay unconscious close to one of the fires. The water from the mozo's canteen revived him, however, and presently he sat up, while the Cahuilla washed the gash in his head and bound it up with his master's bandanna handkerchief.

As the Indian worked, the white man related what had occurred and how.

He recalled his conversation with his a.s.sailant, and shrewdly surmised that he would head for the Colorado river, after having first secured a supply of water at Chuckwalla Tanks. The Desert Rat's plan of action was quickly outlined.

"You will help me to get to the Tanks, where I'll have water and a chance to rest for a day or two until I'm able to travel; then I'll head for the Rio Colorado and wait for you in Ehrenburg. I'll keep one canteen and you can take the other; I have matches and my six-shooter, and I can live on quail and chuckwallas until I get to the river. You have your knife. Track that man, if you have to follow him into h.e.l.l, and when you find him--no, don't kill him; he isn't worth it, and besides, that's my work. It's your job to run him down. Bring him to me in Ehrenburg."

It was past noon when they arrived at the Tanks, and the Indian was carrying the Desert Rat on his back. While the man was quite conscious, he was still too weak from the effect of the blow and loss of blood to travel in the heat.

At the Tanks the Indian picked up the trail of four burros and a man.

He refilled his canteen, took a long drink from the Tank, grunted an "_Adios, senor,_" and departed up the draw at the swift dog-trot which is typical of the natural long-distance runner.

The Desert Rat gazed after him. "G.o.d bless your crude untutored soul, you best of mozos" he murmured. "You have one virtue that most white men lack--you'll stay put and be faithful to your salt. And now, just to be on the safe side, I'll make my will and write out a detailed account of this entire affair--in case."

For half an hour he scribbled haltingly in an old russet-covered note-book. This business attended to, he crawled into the meager shade of a _palo verde_ tree and fell asleep. When he awoke an hour or two later and looked down the draw to the open desert, he saw that another sandstorm was raging.

"That settles it" he soliloquized contentedly. "The trail is wiped out and the best Indian on earth can't follow a trail that doesn't exist, But that wretched little bandit is out in this sandstorm, and the jacks will stampede on him and he'll pay _his_ bill to society--with interest.

When the wind dies down the pack outfit will drift back to this water-hole, and when Old Reliable finds out that the trail is lost, _he'll_ drift back too. Anyhow, if the burros don't show we'll trail _them_ by the buzzards and find the packs. Ah, you great mysterious wonderful desert, how good you've been to me! I can sleep now--in peace."

He slept. When he awoke again, he discovered to his surprise that he had been walking in his sleep. He had an empty canteen over his shoulder and he was bareheaded. His head ached and throbbed, his tongue and throat felt dry and cottony; he seemed to have been wandering in a weary land for a long time, for no definite reason, and he was thirsty.

He glanced around him for the water-hole beside which he had lain down to sleep and await the mozo and the burros. On all sides the vast undulating sea of sand and sage stretched to the horizon, and then the Desert Rat understood. He had been delirious. With the fever from his wound and the thought of the fortune of which he had been despoiled, uppermost even in his subconscious brain, he had left Chuckwalla Tanks and started in pursuit. How far or in what direction he had wandered he knew not. He only knew that he was lost, that he was weak and thirsty, that the pain and fever had gone out of his head, and that the Night Watchman walked beside him in the silent waste.

It came into his brain to light three fires--to flash the S. O. S. call of the desert in letters of smoke against the sky--and he fumbled in his pocket for matches. There were none; and with a sigh, that was almost a sob the dauntless Argonaut turned his faltering footsteps to the south and lurched away toward the Rio Colorado.

Throughout the long cruel day he staggered on. Night found him close to the mouth of a long black canyon between two ranges of black hills, whose crests marked them as a line of ancient extinct volcanoes.

"I'll camp here to-night," he decided, "and early tomorrow morning I'll go up that canyon and hunt for water. I might find a 'tank.'"

He lay down in the sand, pillowed his sore head on his arm, and, G.o.d being merciful and the Desert Rat's luck still holding, he slept.

At daylight he was on his way, stiff and cramped with the chill of the desert night. Slowly he approached the mouth of the canyon, crossing a bare burnt s.p.a.ce that looked like an old "wash."

Suddenly he paused, staring. There, before him in the old wash, was the fresh trail of two burros and a man. The trail of the man was not well defined; rather scuffed in fact, as if he had been half dragged along.

"Hanging to the pack-saddle and letting the jack drag him" muttered the lost Desert Rat. "I'll bet it's little Boston, after all, and I'm not yet too late to square accounts with that _hombre._"

In the prospect of twining his two hands around the rascal's throat there was a certain primitive pleasure that added impetus to the pa.s.sage of the Desert Rat up the lonely canyon. The thought lent new strength to the man. Dying though he knew himself to be, yet would he square accounts with the man who had murdered him. He would--

He paused. He had found the man with the two burros. There could be no mistake about that, for the canyon ended in a sheer cliff that towered two hundred feet above him, and in this horrible _cul de sac_ lay the bleached bones of two burros and a man.

Here was a conundrum. The Desert Rat had followed a fresh trail and found stale bones. Despite his youth, the desert had put something of its own grim haunting mystery into this man who loved it; to him had it been given to understand much that to the layman savored of the occult; at birth, G.o.d had been very good to him, in that He had ordained that during all his life the Desert Rat should be engaged in learning how to die, and meet the issue unafraid. For the Desert Rat was a philosopher, and even at this ghastly spectacle his sense of humor did not desert him. He sat down on the skull of one of the burros and laughed--a dry cackling gobble.

"What a great wonderful genius of a desert it is!" he mumbled. "It's worth dying in after all--a fitting mausoleum for a Desert Rat. Here I come staggering in, with murder in my heart, stultifying my manhood with the excuse that it would be justice in the abstract, and the Lord shows me an example of the vanity and littleness of life. All right, Boston, old man. You win, I guess, but I've got an ace coppered, and even if you do get through, some day you'll pay the price."

He sat there on the bleached skull, his head in his hands, trembling, pondering, yet unafraid in the face of the knowledge that here his wanderings must end. He was right. It was a spot eminently befitting the finish of such a man. It was at least exclusive, for the vulgar and the common would never perish here. In all the centuries since its formation no human feet, save his own and those of the man whose skeleton lay before him, had ever awakened the echoes in its silent halls. Pioneers, dreamers both, men of the Great Outdoors, each had heard the call of the silent places--each had essayed to fight his way into the treasure vaults of the desert; and as they had begun, so had they finished--in the arms of Nature, who had claimed the utmost of their love.

The Desert Rat was a true son of the desert. To him the scowl of the sun-baked land at midday had always turned to a smile of promise at dawn; to him the darkest night was but the forerunner of another day of glorious battle, when he could rise out of the sage, stretch his young legs and watch the sun rise over his empire. He knew the desert--he saw the issue now, but still he did not falter.

"Poor little wife," he mumbled; "poor little unborn baby! You'll hope, through the long years, waiting for me to come back--and you'll never know!"

His faltering gaze wandered down the canyon where his own tracks and those of the dead shone gray against the brown of the sun-swept wash. He had followed a trail that might have been ten years old; perhaps, in the years to come, some other wanderer would see _his_ tracks, halting, staggering, uncertain, blazing the ancient call of the desert: "Come to me or I perish." And following the trail, even as the Desert Rat had followed this other, he, too, in his own time, would come at length to the finish--and wonder.

The Desert Rat sighed, but if in that supreme moment he wept it was not for himself. He had many things to think of, he had much of happiness to renounce, but he was of that breed that dares to approach the end.

Like one who wraps the drapery of his couch.

About him, and lies down to pleasant dreams.

For him the trail had ended here, as it had for this other remnant of vanished life that lay before him now with arms outstretched. The Desert Rat stared at the relic. A cross! The body formed a cross! Here again was The Promise--

A thought came to the perishing wanderer. "I'll leave a message" he gobbled. He could not forbear a joke. "To be delivered when called for" he added. "This other man might have done the same, but perhaps he didn't care--perhaps there wasn't anybody waiting at home for him."

From his shirt pocket he drew the stub of a lead pencil and the note-book in which he had written his will and the record of his betrayal. He added the story of his wanderings since leaving Chuckwalla Tanks, and the postscript:

The company in which I will be found was not of my own seeking.

He was here before me by several years and I found nothing whereby he might be identified.

He tore the leaves out of the note-book, stuffed them inside his empty canteen and screwed the cap on tight; after which he cast about for a prominent place where he might leave his last message to the world.

At the head of the canyon stood an extinct volcano, its precipitous sides forming the barrier at the western end of the canyon. Away back in the years when the world was young, a stream of thin soupy lava, spewed from this ancient crater, had flowed down the canyon out onto the desert. It was this which the Desert Rat had at first taken for an old "wash." Owing to the pitch of the canyon floor, most of the lava had run out, but a thin crust, averaging in thickness from a quarter to three quarters of an inch, still remained. Originally, this thin lava had been a creamy white, but with the pa.s.sage of centuries the sun had baked it to a dirty brown and the lava had become disintegrated and rotten. As the hot lava had hardened and dried it had cracked, after the fashion of a lake bed when the water has evaporated, but into millions and millions of smaller cracks than in the case where water has evaporated from mud.

As a result of this peculiar condition, the entire lava capping in the canyon was split into small fragments, each fragment fitting exactly into its appointed place, the whole forming a marvelous piece of natural mosaic that could only have been designed by the Master Artist.

With the point of his pocket knife the Desert Rat pried loose one of these sections of lava. Where it had been exposed to the sun on top it was brown, but the under side was the original creamy white.

The mystery of the phantom trail was solved at last. In fact, not to state a paradox, there had been no mystery at first--at least to the Desert Rat. The moment he saw the bones he guessed the answer to that weird puzzle.

The tracks were easily explained. When one walked on the surface of this thin lava crust it broke beneath him and crumbled into dust. The brown dust on top mingled with the underlying white, the blend of colors on the whole forming a slate-colored patch with creamy edges, marking the boundaries of the footprints; and here, in this horrible canyon, where rains would never erode nor winds obliterate, the tracks would show for years until the magic of the desert had again wrought its spell on the landscape and the ghostly white tracks had faded and blended again into the all-prevailing brown.