The guide came wriggling like a snake, working himself forward upon his elbows and his knees, almost flat upon his face, which was little raised above the ground. His dark features were expressionless. Upon his countenance was visible no sign of triumph, no elation at a victory that was well within his grasp. As he came nearer and nearer his dark eyes never moved from the stern face of the Arab sheikh.

Then slowly he rose to his feet, bringing the butt of his rifle into the hollow of his shoulder.

"Bayram," said he in a deep voice, "make your peace with the Almighty God, for you are about to die!"

The Arab extended his arms in the direction of the east. Beyond the mountains, on the far horizon, the sun was setting in a glow of crimson glory. The great hills stood forth before the sunset like the thrones of giants, their irregular, rugged outline a deep leaden colour where they were not wrapped in gathering clouds.

The Black Dog lifted his voice so that it carried far across the valley.

"Without repentance," said he, "I go into the shades. I have sometimes acted unwisely, for human flesh is weak, and man cannot have the wisdom of Allah, whose prophet is Mohammed. But for such false steps as I have taken I am ready to pay the price. Come, fire, and have done with it! I do not fear to die."

There was no question that Fernando was about to fire, when Harry cried out in the nick of time.

"The Sunstone!" he exclaimed.

The sheikh turned to the boy and smiled, his white teeth showing in his beard. Then he thrust a hand into a pocket and drew forth the Sunstone, which he held to the light, so that the yellow jade caught the reflection of the dying sun and looked like the most magnificent of opals.

"Here it is," said he. And then to the guide: "Will you take this in exchange for a human life? I am ready to strike a bargain."

Fernando shook his head.

"Do as he bids you," pleaded Harry, who was not only anxious to recover the Sunstone at every cost, but who had no liking for this business, which was in the nature of a common execution.

"I have sworn an oath," said the guide in measured tones. "The Black Dog must die."

With these words he approached, until he was quite near to the Arab. It was no doubt his intention to shoot the man and then grasp his robes to prevent his lifeless body from falling over the cliff. Be that as it may, he failed in his enterprise, for the sheikh was possessed of the supple activity of a tiger as well as the cunning of a wolf.

Fernando raised his rifle. He was then not ten feet from the Arab. And even as he pressed the trigger the Black Dog sprang upon him, striking the barrel of the rifle upward, so that the shot flew high in the air.

A second later the two men were locked together in a death-grip, each struggling desperately for life.

The sheikh was the stronger of the two, but he suffered from his wound. Not only was he somewhat weakened by loss of blood, but his right leg, the flesh of which had been torn by the leopard's fangs, was stiff and aching from the great fatigue of the journey across the mountains.

Harry put down his rifle and came forward in all haste, his revolver in his hand. He desired to give what help he could to the guide, but this was no easy matter.

The two men were like fighting cats. First one was on the top and then the other. They rolled over and over so rapidly, and were so closely interlocked, that it was almost impossible to tell which was the guide and which the sheikh. Sometimes they struggled at the foot of the cliff; at others they were on the very edge of the precipice, and both seemed in imminent danger of falling into the depths.

"Help!" let out Fernando in the voice of one who choked. "He fights like a demon possessed!"

Harry, in desperation, hurled his weight upon the two, and at once found his strength of small avail. He was tossed hither and thither, and was more than once in danger of being hurled over the edge.

At last, not without difficulty, he disengaged himself, recognizing that he did no further good than risk his life. He saw also that his revolver was quite useless. He dared not fire, even at the closest range.

It was then that Fernando somehow managed to release the other's hold, and sprang sharply to his feet. The sheikh was on him again like a wild cat, and had him by the throat. Putting forth the whole of his colossal strength, the Black Dog forced the other backward.

Nearer and nearer to the edge of the precipice the four feet shuffled, until the guide actually tottered on the brink.

Harry stood by-a helpless spectator, petrified with horror. The terror of the situation had taken his breath away. It was as if he had lost all power and all sensation of his limbs. Then, with a loud cry, Fernando, hurled from the Black Dog's powerful grasp, plunged feet foremost over the cliff.

And as he fell he grasped the air with frantic, clutching hands, in an agony of brief despair. His left fist closed upon nothing, but his right laid hold upon the long, flowing robes of his opponent.

On the instant the Black Dog was jerked off his feet. He tried to save himself by throwing his weight backward-a quick, spasmodic action that proved that he retained his presence of mind to the end. He was too late, however. His shoulder struck the tooth-like edge of the precipice-and, in a flash, he was gone.

Harry Urquhart felt the strength suddenly go from his knees. Unable any longer to stand, he sank down into a sitting position on the narrow, perilous path. His heart was beating like a hammer; for a moment he thought that he would faint.

He dared not look down into the abyss. It was all too horrible to think of. He sat still and listened, while the sun sank beyond the mountains, and darkness crept into the valley. A great silence reigned among the hills that was like the silence of the tomb.

CHAPTER XXXIV-The Sunstone Found

More than an hour elapsed before Harry Urquhart had the power to move. The whole tragedy had been far more terrible than any nightmare, and yet he felt just like a little child that awakens suddenly in the night, to find himself still confronted with those horrid possibilities that can only occur in dreams.

Night crept into the valley from the east. The glow in the heavens died out, and one by one the stars appeared, and a great full moon, luminous and white. The boy crept to the edge of the precipice and looked over. He could see nothing; it was too dark to see. The whole valley was still.

This silence was fearful in itself. It seemed to Harry that he was the only living thing in the world. There were no voices in the night; in the valley there was no sound of bird or beast or human being.

Harry rose to his feet, and, step by step, aided by the moonlight, cautiously returned to the spur by way of which he had come. He was still quite unnerved. He dared not go near the edge of the precipice; as he advanced he clutched the mountain-side. When he came to the spur he clambered down among the rocks in such haste that the perspiration stood in beads upon his brow. And then a feeling of weakness overcame him again; and, seating himself upon the ground, he endeavoured to think matters out.

He tried to realize the full significance of what had happened. Fernando had fulfilled his oath: he had brought about the death of the Black Dog of the Cameroons. But he himself had perished also, and the Sunstone had been lost. And all had happened in the space of a few seconds, about which it was terrifying even to think.

Above all else, Harry Urquhart wanted someone to talk to; he wanted to hear the sound of a human voice. He was still like a child awakened from a nightmare. The loneliness of this great, howling wilderness was crushing, overpowering. With his nerves overwrought, his courage shaken, the eternal silence got the better of his feelings, and suddenly, burying his face in his hands, he burst forth into tears.

He knew not why he cried. His tears were not tears of sorrow. He cried because he had passed through a great ordeal, because he had been face to face with Death. And, in that sense, every teardrop was the word of a prayer to the God who controls the destinies of men.

Then, mastering his emotion, he rose to his feet and went on-he knew not whither. After a time he came to a stream, and there he stopped, wondering what to do.

There was food in his haversack, but he felt no inclination to eat. He went down on his knees, and drank deeply. The water was very cold.

When he had quenched his thirst, which was like the thirst that accompanies a fever, he felt refreshed. He even scorned himself for having been so weak. It was then that he looked about him.

He was shut in on all sides by the great inhospitable mountains. Above was a clear sky, bespangled with a multitude of stars, in the midst of which the full moon shone down into the valley. Then he saw another star, solitary, large as a planet, lower than the others. It was a star that seemed to shine from out of the heart of the mountains.

It was some minutes before he realized what it was. Then the truth came upon him as in a flash. It was not a star at all, but a camp-fire that was burning on the hill-side.

The thought that he was not alone in this desolate and silent region was like the nectar of the gods to one who is faint and weary. The boy cared not in the least who camped on the mountainside; he decided to find out for himself. If they were savages, they could murder him; it would matter little to him. If they were friendly, they might allow him to warm himself by the side of the glowing embers. At any rate he would hear some kind of human speech.

It took him three hours to reach the fire, where he found two men, seated facing one another. A cry of exultation escaped his lips when he recognized Jim Braid and the younger guide.

At once Cortes sprang to his feet as if alarmed.

"Where is my brother?" he asked.

Harry tried to speak, but was not able to do so. He sank down by the side of the fire.

"Some calamity has happened!"

Harry bowed his head.

"And the Black Dog?" asked Cortes.

"He also is dead," said Harry, speaking for the first time.

"Dead!" cried Cortes, without expression in his voice.

"Yes," said Harry. "And the Sunstone is lost, and von Hardenberg will starve to death in the Caves of Zoroaster."

Cortes seated himself once more upon the ground, extending his hands towards the fire. There were no tears in his eyes; his voice was without a tremor.

"When you feel able to do so," said he, turning his face to Harry, "will you please tell me what happened."

Harry related the story from beginning to end. He told how Fernando and himself had followed the sheikh across the mountains, and of how they had run the man to earth upon a narrow ledge at the top of an enormous cliff. He then described the struggle that had taken place, with its grim and terrible conclusion.

When the boy had finished speaking, Cortes looked up at the moon.

"In four hours," said he, "it will be daylight. We can do nothing till then. When the dawn comes we will search for the bodies."

At that he lay down upon the ground, but it was evident he had no intention of going to sleep.

He had shown little or no emotion on hearing of his brother's death. There was black blood in his veins, and, with the more savage races, death is a simple and everyday affair. For all that, there is no reason to suppose that he did not feel the great loss he had sustained.

A long time elapsed before Harry, too, was able to sleep. And, when at last he did so, he was for ever struggling on the brink of an unfathomable abyss, so that he was little rested when at daybreak he was awakened by Cortes.

Without waiting for food, they set out at once upon their way, passing slowly down the hill-side. They soon reached the stream, and thence turned to the south. It was Harry who led the way. When he judged that they were parallel to the place where the tragedy had happened, they crossed the stream and walked straight for the cliff.

At the foot of the precipice was a kind of terrace, upon which grew scattered trees, about the roots of one of which were boulders. Lying on his back, across one of these rocks, they found the body of the Black Dog of the Cameroons.

The two boys looked away whilst the guide examined the body, and then, stooping, picked up something from the ground. Presently Cortes touched Harry on the arm.

The boy turned and set eyes upon the Sunstone.

CHAPTER XXXV-A Brother

Leaving the body of the wretched man where they found it, they continued to search among the trees; but nowhere could they discover any trace of the elder guide.

"His body cannot be far away," said Harry. "They fell together."

It was then that, at the sound of a faint cry from somewhere far above them, all three looked up. And the sight they beheld was appalling.

Hundreds of feet above the place where they stood, sheltered by a cranny in the face of the cliff, there grew a gnarled and twisted shrub, a kind of withered tree. In the midst of this, caught like a fish in a net, was a man who, even as they watched him, moved, twisting like a thing in pain.

Cortes scanned the face of the cliff; but, look where he might, he could discover no way by which it was possible to ascend to the place where his brother was suspended in mid-air.

Running back several yards, he regarded the precipice above the withered tree. It was equally inaccessible from above. Then he raised his hands to his mouth and cried out in a loud voice, calling upon his brother by name.

The answer came in a voice so weak that Cortes had to hold a hand to an ear in order to catch the words.

"I am in pain. My arm is broken. Can you not come to my assistance?"

The younger brother looked about him in despair.

"Can nothing be done?" asked Harry.

"Let me think," said Cortes, and lifted a hand to his eyes. On a sudden he cried out to his brother. "Can you hold out for two days?" he asked.

"For two days!" came the answer. "It is too long."

"You must!" cried the other. "Take the belt from your waist and bind yourself to the tree. Then, when your strength is gone, you will not fall."

Whilst the elder man obeyed these injunctions, Harry turned to Cortes.

"What do you intend to do?" he asked.

"We have no rope," said the guide. "Fernando is at least fifty feet from the path above, and there is no rope fifty feet in length nearer to this place than Kano or Sokoto. However, there is-as you know-a rope-like creeper that grows in the bush. I intend to go back as far as the jungle."

"Can you get there in time?" asked Braid, incredulously.

"My wound is now healed," said the man, "my strength returned. I can but do my best."

Cortes looked up again at his brother.

"Courage!" he cried. "In two days I return."

So saying, he bounded off upon his way. As they watched him pass down the valley, springing from rock to rock, it was apparent that he meant to do all that was humanly possible to effect the salvation of his brother. Even as they looked, his figure grew smaller in the distance, and in a few minutes he was lost to view.

To describe in detail the journey of the younger guide across the mountains would be tedious. The thing can be summed up in a few words: it was magnificent, heroic. Mile upon mile he covered without pausing for breath. For the most part he kept to the valleys, where the atmosphere was stifling and humid, crossing the mountains only when by doing so he could cut off several miles.

He had food with him, but he seldom stopped to eat. Now and again he drank at a mountain stream, but seemed to grudge the time even for this.

At sunset he was still bearing onward. He had cast aside the greater part of his clothing, and the perspiration poured off him, and the veins stood out upon his temples like knotted strands of cord. For all that, he went on and on beneath the stars, whilst the moon marched in the heavens. It was a race for the life of his brother.

As Cortes hastened on his way, his thoughts continually went back to the perilous situation in which he had left Fernando, and every thought was, as it were, a spur to his endeavour. No sooner had he pictured in his mind's eye that struggling, writhing figure, hanging, as it were, betwixt earth and sky, than he shot forward with renewed energy, clenching both fists and teeth in his strong determination.

At last, breathless, exhausted, he sighted the extremity of the great West African bush. Through this, forcing his way among the thickets, so that the sharp thorns tore his naked flesh, he was obliged to travel for many miles before he found the right kind of creeping plant, and, moreover, one long enough to suit his purpose.

To cut this from the tree around which it was twined, and roll it into a great coil which he suspended around his neck, was the work of not many minutes; and then he set forth upon his return journey to the margin of the desert.

He was already much exhausted, and his load was very heavy. But hour by hour he struggled onward, leaving the jungle far behind, mounting to higher altitudes. Nightfall found him still upon his way. Repeatedly he stumbled, and then, on a sudden, he fell full length upon the ground.

He lay quite still for several seconds, then rose slowly to his knees, lifting his eyes and hands towards the stars. For a moment he prayed silently; and, seeming to gather courage from his prayer, he rose to his feet and went on.

Soon after midnight the sky became overcast. A high wind got up and blew from the mountains, bitter cold after the tropic heat of the bush. Then the skies opened and the rain came down in sheets. But Cortes still held on, struggling towards his goal, fighting manfully against his own failing strength.

And in the meantime, throughout these two fearful days, Jim Braid and Harry waited in suspense. They could do nothing to help the man who hung, hour after hour, upon the brink of the other world.

Acting on his brother's advice, Fernando had undone the belt around his waist, and with this had lashed himself to the stoutest branch of the tree. Words fail to describe the torture he must have suffered; for, not only did he endure great pain from his broken arm, but he was tormented by a raging thirst. His cries for water were piteous to hear.

They had no means of assisting him. They could do nothing but look on in helplessness, praying for the return of the younger brother. On the second night the rain came-in torrents, as it can only rain in the tropics-and Fernando was able to moisten his parched lips by sucking his drenched clothes.

Wishing to get nearer to the poor fellow, in the hope that they might be able to comfort him, at least with words, Harry and Jim Braid climbed the spur and moved along the ledge at the top of the precipice until they were immediately above the withered tree. There, lying down upon their faces, they cried out to him to be of good courage, reminding him that the dawn approached, that his brother would soon return.

Daybreak is the hour when Life is nearest Death. It was shortly before sunrise that Fernando himself gave up all hope, and called upon God to take charge of his departing soul. He said that he was quite ready to welcome Death; he desired nothing more than to have an end to his misery and suspense. And, even as the words left his lips, the figure of his brother was seen approaching along the ledge.

At the feet of Harry Urquhart, Cortes sank, exhausted. The object of his mission fulfilled, he lost consciousness and drifted into a faint.

With all dispatch they uncoiled the long, snake-like creeper. Passing one end over a jutting pinnacle of rock, they lowered the other towards Fernando. It was more than long enough to reach the place where he lay.

With great difficulty the poor fellow managed to untie his belt and make fast the end of the creeper around his waist. And then they had to wait a long time, until Cortes, who had recovered consciousness, was able to assist the two boys in hauling up the rope.

This was no easy matter, since they had neither a good foothold nor much space upon the terrace. But in the end they succeeded, and the rescued man lay panting on the ledge. He was immediately given water to drink; and when he had drunk, a smile slowly overspread his face, and he looked at the brother who had saved his life. But no word of gratitude ever passed his lips; his thanks-far more eloquent than words-were in his eyes. And the dark eyes of a half-caste are the most expressive and the most beautiful in the world.