“Doubtless some kind of a knife,” Dr. Kirshner said, as the others crowded around him. “Shaped out of flint by people of the Neolithic age. Perhaps it was used to harvest crops.”
“Crops? In the desert?” Bob was amazed.
The scholar nodded.
“It is firmly believed that primitive people lived in what is now the desert rather than along river valleys of more modern prominence. Of course the Sahara was at that time much less arid, or dry, than it is today.”
Dr. Kirshner searched about for other relics, but found none.
“It is strange how that tool got on the surface of the ground,” he remarked, as they turned the dromedaries ahead. “Other expeditions havepenetrated into this region, and it is quite obvious that they would have found it had it been in sight.”
“Perhaps a rainstorm washed it out of the ground,” suggested Mr. Holton.
They rode until late that night, for they were anxious to come to the gorge of Arak some time the next day.
“We should see it tomorrow afternoon,” predicted Fekmah.
Notwithstanding this, they rode all the next morning without coming to the landmark. Finally Tishmak gave up in disgust and stopped in the shade of an overhanging rock. It was nearly noon, and the necessity to get a meal was becoming more apparent.
When they had finished eating they continued to rest in the tent. At this high altitude the sun was less hot than it had been on the plateaux, and it would have been possible to ride farther. But they had become accustomed to the usual afternoon rest and were loath to depart from this regularity.
But Dr. Kirshner had sat only a few minutes before he got up and stretched. Mr. Holton and Mr. Lewis were asleep, but Fekmah and Tishmak remained awake. Bob and Joe sat in one corner of the tent, sleepily gazing out at the distant peaks.
“I’m going out and look around,” Dr. Kirshner said to them. “Care to go along?”
Bob replied in the negative, but Joe arose and walked over to his rifle.
“Don’t stay too long,” advised Bob, as Joe and the archæologist started out.
They were familiar with the country in the immediate vicinity of camp. As there was nothing of new interest to be found there, they hiked farther to the south. The scientist wished particularly to find more ancient inscriptions, and, if possible, other evidences of ancient civilizations.
“What’s this?” cried Joe, slapping his hand to his face. “Well I’ll be—— Some kind of a fly.”
“It is a wonder we haven’t come across insect pests long before this,” Dr. Kirshner said. “They are very common all through this section.”
The flies had been discovered while they were trudging through a long, hot passageway between two high wall-like rocks. Now, as the two adventurers passed farther on, they came into more of the insects, which swarmed about as if thirsty for human blood.
“Ought to have some kind of a spray,” remarked Joe, pushing them away in great numbers.
“We have, in camp,” his friend said. “If the pests bother us much we’ll have to make use of it.”
After an hour’s hike they came to another dryriver bed, and again Dr. Kirshner found flint implements scattered about. Joe had a small motion-picture camera with him, and at the scientist’s request he filmed the half-buried primitive tools as they lay hardly visible in the sand.
“I want proof that these antiquities came from the Sahara,” Dr. Kirshner said, placing them in the small box he carried over his shoulder for the purpose.
A little later Joe started to take a motion picture of a small animal that darted across the river bed, but cried out in disgust.
“A pesky fly got in front of the lens,” the youth explained. “Looked as big as an elephant.”
“One scene ruined,” laughed the archæologist. “But you’ll have to get used to that.”
The adventurers stopped here and there to rest and sip a small amount of water. Then they would hike on, always on the lookout for the unusual.
They had just rounded the corner of a tall, cone-shaped peak when Joe stopped and pointed to the sand near by.
Dr. Kirshner’s jaw dropped in surprise.
“Footprints!” he cried. “Human footprints!”
He had hardly uttered the words when there came a chorus of yells from behind a large rock. A moment later ten or twelve rough-looking Arabs darted out and surrounded the Americans. The natives at once disarmed the whites by sheerforce and then displayed long knives threateningly.
The Arabs chattered ominous words, which caused Dr. Kirshner to start in alarm and fear.
“We are being captured!” he exclaimed excitedly. “These Arabs are hired by the two thieves who stole Fekmah’s map!”
ATDr. Kirshner’s dread explanation, Joe cried out in surprise and fear.
“Captured!” he mumbled in a strange voice. “Find out how long they are going to keep us.”
The scientist put the question before the Arabs, who laughed mockingly.
“Until the treasures have all been taken from the hidden cave,” they replied in the native language.
Dr. Kirshner could hardly believe his ears.
“Then—the riches have been found?” he demanded.
“Yes. And we are to keep you away. We know not how long it will be. If you act right, we will treat you well. But if you try to get away you will be severely punished.”
“Where are you taking us?”
For answer the Arabs only laughed.
“What do you think of it?” asked Joe, after his friend had translated the natives’ words.
Dr. Kirshner shook his head.
“Looks like we’re not going to get back to camp today,” he said gravely. “Worst thing is, these rascalsmay hunt out our friends and capture them also. If we could just leave some word that would give them a hint to be on the lookout——”
The two Americans were forced along the narrow edge of a deep canyon, and more than once they felt that they were but an inch from death. Their tempers were thoroughly aroused, but they knew that they had no chance against such a horde.
“These fellows are a bit different from American roughnecks,” Dr. Kirshner said. “Arabs would not hesitate to stick a knife through you if not satisfied with your actions, but our own countrymen would ordinarily think twice before doing such a thing.”
The two explorers were in the midst of the group, with swarthy natives on each side of them. To attempt to break loose would indeed be futile.
“I wonder if we will be taken near the hidden riches?” muttered Joe, gazing ahead at the distant country.
“Hard telling,” the archæologist replied. “Of course it is possible, but I doubt it. Still they might purposefully show us the treasure to let us know how much we are missing.”
A half-hour’s traveling brought them to the base of an unusually high peak. It might, thought the Americans, be Mount Oudane or Illiman, as it was every inch of ten thousand feet.
There was a small well in a crevice between the rocks, and much to their great delight the prisoners were given the opportunity to drink to their hearts’ content. The water was unusually cool, protected as it was from the heat of the sun.
But only a few minutes’ rest was allowed, even though the Americans were very tired after the ceaseless afternoon tramp.
Another hour of hiking over the rough country brought them to a high hill, which Dr. Kirshner said led to the central plateau of Atakor. For a great distance it was almost flat country, with little or no vegetation.
The prisoners were forced to climb a narrow ledge and came at last to the top of the mountain. To their right was a large entrance that led undoubtedly into a cave.
The Arabs motioned for the whites to stop and turn into the cavern. Dr. Kirshner and Joe hesitated for a moment then did as directed.
At first they found themselves in utter darkness. As their eyes became more accustomed to the blackness, they saw that a long, narrow tunnel stretched away from the back of the cave. Whether it led to any place in particular they did not know.
“Well, I guess we’ve come to the end of our tramp,” observed Joe, looking about to see what the Arabs intended to do next.
There were no chairs or boxes to sit on, but slabs of rock invited the newcomers to sit down.
As soon as it became evident that the Americans had settled themselves, the Arabs stationed themselves at the entrance of the cave. Before long, however, all of the men but three departed.
“Looks bad for us,” remarked Dr. Kirshner. “We were fools to start out alone in this country when we knew we were getting near the hidden riches.”
“Too late now,” mourned Joe. “We’ll have to make the best of it, I guess. But I’d feel a lot better if we had some way to warn Dad and Bob and the others. Perhaps they’ll walk right into a trap set by those Arabs.”
The cave in which they were guarded was in the side of a wall of rock, which was several hundred feet above the surrounding mountains. From their lofty positions the Americans could look out over scores of miles of rugged country.
Dr. Kirshner had his binoculars strapped over his shoulder and took them out to view the distant panorama. The binoculars were of very high power, made by a well-known firm.
Suddenly his eyes fell on something that made him gasp in astonishment.
“The cave of riches!” he cried. “I can see it! And there are five or six Arabs walking inside!”
DOWNa little valley between two high mountains rode four explorers, their eager eyes penetrating every crevice and notch in the mountainous country about them. High-power binoculars were turned upon every level stretch, rifles were fired at regular intervals, voices were brought to new swells. It was a search that under ordinary circumstances would have brought Dr. Kirshner and Joe back in a very short time.
Finally, after the searchers had been out several hours and darkness was beginning to fall, Mr. Lewis stopped and buried his face in his hands. He realized that defeat was staring them in the face.
“Guess they’re really lost,” sighed Bob Holton, his face extremely sober.
“Or else something has happened to them,” added Fekmah in a voice that he tried to keep steady.
Mr. Lewis said nothing, but he feared all too much that the Arab was right. And yet, he reasoned,they were likely to be very careful and not take chances. Still that would not prevent nature or wild tribes from harming them.
Mr. Holton, however, was very optimistic. He believed that, despite the length of their stay, the two were safe. Perhaps they had fallen asleep from exhaustion or had wandered farther away than they had intended and were forced to spend the night in the mountains.
Tishmak had been left at the camp, as it was thought best to have someone there in case the archæologist and Joe should return while the searchers were gone.
“We’re a long distance from camp,” said Mr. Lewis, as the searchers sat on their camels at the brink of a deep gully. “Shall we try to get back tonight?”
“I’m in favor of it,” returned Mr. Holton impatiently. “Of course we left word with Tishmak that we might spend the night away, but he may be greatly worried. Then, too, he might not be safe there alone.”
The others thought this good advice, and turned the dromedaries back up the lane. They could possibly get half of the way there before the darkness would halt them. Then the moon would probably furnish sufficient light to continue.
“Here’s hoping they will be at camp when we get there,” said Bob.
But Tishmak was the only one who greeted them when finally they rode wearily up to the tent.
The guide had fully expected to see the lost ones return with the others, and his face wore an anxious look when he saw that their search had been in vain.
Fekmah immediately related their past experiences, concluding by asking what Tishmak thought had happened to them.
The guide replied that, as Mr. Holton had said, perhaps they had wandered farther away than they had intended and were forced to spend the night away. Of course, he went on, tragedy might have come upon them, but he doubted this very much. The Tuaregs who inhabited this region were friendly to strangers, showing excellent hospitality. And both Dr. Kirshner and Joe he considered able to take care of themselves. He finished by saying that, through his guiding numerous expeditions into the Sahara, he believed himself capable of judging a true explorer.
When Fekmah translated this to the Americans, they were much relieved. Especially was Mr. Lewis hopeful. He had confidence in Joe and believed him equal to taking care of many tight situations.
Notwithstanding this, there was little sleep for any of them that night. When at last the sun beganto peep through the distant mountains they were up ready for action.
“We’ve got to find them today,” said Bob, gritting his teeth.
“We will, if they are anywhere around here,” Mr. Lewis added. “Let’s hurry and have breakfast.”
As soon as the meal was over, they again started out on the search, this time taking Tishmak and leaving Fekmah. The latter thought this the best procedure, as the guide could render more assistance in searching the mountains.
Taking the opposite direction from the one they followed the day before, the explorers rode off, bidding warm farewells to Fekmah.
For several miles they rode over the smooth surface of a dry river bed. Then they turned and followed a path around a small mountain.
“Wonder how this path got here?” said Joe, as they plodded up the hill.
“Wasn’t made by nature,” concluded Mr. Holton, observing the regularity that was persistent with every step.
He resolved to use his limited knowledge of the native language and inquired of Tishmak, for surely the guide would know.
When finally the latter understood, he replied that the lane had been made by Tuaregs who inhabitedthis region. Perhaps the path would lead them to a village.
But the searchers trudged on around the hill without seeing any signs of natives. However, they finally broke away from the narrow way and emerged on level country.
They were now on a high plateau, with towering peaks on all sides of them. As far as the explorers could see, there were no breaks or ravines anywhere about.
Rifles were discharged at intervals, and hoarse shouts often rent the air. At every few steps the searchers stopped to look about, almost expecting eventually to find the lost ones nearer than they thought.
Once Bob thought he heard footsteps, but several minutes of listening convinced them that no one was about. Perhaps it had been his imagination.
“Sounded like someone was coming toward us,” the youth said. “But I guess I just thought so.”
“We’ll have to keep our ears and eyes wide open,” Mr. Lewis reminded them. “If Joe and Dr. Kirshner are anywhere around here, it might be possible to hear them.”
“Isn’t likely that they fell into the hands of Tuareg raiders, is it?” asked Mr. Holton.
“Tishmak said not,” Joe’s father returned. “Hethinks that the Tuaregs around here are friendly and peaceful.”
A little farther on they passed several large slabs of rock that were covered with ancient inscriptions and drawings. Dr. Kirshner would surely throw a fit of delight if he could see them. But, thought Bob, perhaps he had already come to them and was searching for more, quite forgetful of the necessity to get back to camp. But no, this could not be, for Joe would realize that necessity if the scientist did not.
At noon they stopped for lunch under a large crag that resembled an inverted hook. There was plenty of water in their containers, giving each the opportunity to satisfy his thirst.
There was not much conversation during that rest, for they were all busy with their thoughts. And those thoughts were anything but cheerful. But they refused to give up hope so soon, for another half-hour might see the two lost ones back with their friends.
Scarcely ten minutes were spent in the shade of the rock. Even then Mr. Lewis felt that that time had been wasted.
“Something might have happened to them during that time,” he said, greatly worried.
Mr. Holton laid a hand on his friend’s shoulder.
“Snap out of it, Ben, old man,” he begged. “I’mwilling to bet that they are safe and well. And I firmly believe we will find them before another day will pass.”
Mr. Lewis did resolve to cheer up and be hopeful; but still he possessed a haunting fear that perhaps tragedy had come upon them.
The sun blazed very hot that afternoon, scorching the already baked soil. This did not hinder the progress of the searchers, however, who trudged constantly on.
Suddenly, as they passed over a wide valley strewn with rocks and dotted with cracks and ravines, Bob stopped and looked about expectantly. The others had also caught a sound.
The next moment the explorers were seized with fear, for ten or twelve evil-looking Arabs darted out on dromedaries and rushed toward the explorers.
“What’s this!” cried Mr. Holton, as one of the men caught hold of his camel.
There was no chance to use their guns. The Arabs were on the lookout for any treachery.
Suddenly Bob saw a chance and, drawing the reins of his dromedary, he dashed away at full speed for a short canyon between the rocks.
URGINGhis dromedary on to the utmost, the youth was carried over the narrow valley at a pace that ate up the distance surprisingly. In fact, never had he traveled so rapidly on camelback.
When he was several hundred feet away, he glanced back, to see that two of the Arabs were pursuing him desperately. At the start he had put a good distance between himself and his enemies, but now the latter were gaining swiftly. They were more familiar with the country and knew better how to command their camels to move fast.
“If I can only make that little canyon,” the youth thought, bending low so as to lessen the wind resistance.
The canyon was near now, but a hurried look over his shoulder told Bob that the Arabs were near also. If he could only get there!
He lashed the dromedary with a new determination and entered the narrow way between the mountains just as the Arabs passed over a small grove of low shrubs some two hundred feet away.
Bob knew that this was a very short canyon and that there were numerous large rocks and crevices at the opposite end. Perhaps he could successfully evade his pursuers by hiding in one of these openings in the mountainsides.
Sharp jagged crags protruded from all sides of the thread-like passageway between the high walls. It was very dangerous to ride with much speed in such a place, but the chance had to be taken.
He reached the other end of the passage with but a moment to spare. Immediately his dromedary was cut over to the right behind a barrel-like rock. But the youth did not stop there; he wound in and out among the many huge boulders.
At last he came to a stop in a large crevice between two imposing slabs of stone. With every nerve on edge, the young man listened.
“They’re coming!” he thought, getting out his revolver. “But they won’t get me if I can help it!”
But he was in a very secure hideout, and it was unlikely that the Arabs would locate it. Still he realized that they probably knew this region better than did he.
As Bob waited breathlessly, his mind was in a whirl. Who were these Arabs? What did they want? Why had they descended upon the little exploring party so mysteriously? Bob did not know what to make of the situation, but he knew thatdanger was at hand. What further added to his perplexity was the fact that Arabs did not normally inhabit the Sahara so far south as this.
Suddenly he started, as a thought struck him. Was it—the two thieves who stole Fekmah’s map? Entirely possible, of course.
Then a strange thing happened. As though informed by some unseen power, Bob grasped the whole situation. He saw Dr. Kirshner and Joe in the clutches of the two thieves, being held as prisoners. He visioned his father, Mr. Lewis, and Tishmak riding away under the guard of the Arabs.
“Those thieves did it, then, to keep us away from the hidden treasure,” thought the youth, and he could not have had a more accurate realization.
For some time he listened closely for any sound from the two Arabs who had pursued him. He thought once he heard the footsteps of camels, but was not sure.
What was he to do next? He was now doubly glad that good fortune had enabled him to escape from the would-be captors. If the Arabs had been nomad plunderers, he would probably not have suffered much by remaining with his father and the others. But as it was, there was a possibility of bringing rescue to his friends.
“How am I to do it?” the youth mused, trying to remain calm.
Suddenly the far-away noise of footsteps came to his ears, and he knew that the two Arabs who had followed him had given up and were abandoning the chase to join their friends back in the valley.
After several minutes of waiting, Bob got off his camel and tethered the brute to a small protruding rock. Then he walked over to some distance beyond the mountain near which he had been hiding.
He glanced up to the top of the peak and saw that it was unusually high. The sides stretched almost straight up.
“If I could only get to the top of some tall mountain,” Bob thought, his eyes scanning the landscape. “Then I might be able to see where Dad and the others will be taken.”
The peak before him offered no footholds and therefore could not possibly be scaled. He looked about for other sky-piercing hills. At last his eyes fell on one about a hundred yards away, and he resolved to inspect it.
“Looks like there might be a chance there,” the youth thought and then walked over and untied his dromedary.
He rode over to the mountain, every step bringingnew hope. The peak, rocky as it was, was rather gradual and not straight up, as were many others in the vicinity.
Once more the camel was tied by the rocky side, and Bob moved over to gaze up to the top. The dizzy height almost took his breath away. But he saw at once that it would be possible to climb to the very summit of this imposing peak of rock.
Bracing himself to the task that was before him, Bob began the dangerous ascent, slowly, at first, and then climbing faster. It was exhausting, fear-inspiring, but he went bravely up. There was no option in this case. He must observe where his father and the others would be taken by their Arab captors.
“If I can only get up in time,” the young man thought, as he sought out a means to ascend a five-foot plate of smooth stone that was directly above him.
To do this, it was necessary to edge on around the mountainside until he came to a rough, gradual section. Then climbing became comparatively easy.
Once, when he was but a third of the way up, he glanced back over his shoulder to the ground below and almost lost his balance. But he caught himself with a quick motion, and after resting a moment from the terrific strain, continued the climb. That glance to the ground had revealedthat he was several hundred feet up. How easy it would be to slip backwards!
Another hundred feet and he found himself on a wide shelf, which seemed to encircle the peak. A short rest was taken here, and in the end he felt much better for it.
“Wonder if I can get down from here?” the boy mused, again taking up the climb. “I’ll find some way, though,” was his conclusion.
For a few more hundred feet the way was very gradual, with many rocks of different sizes affording footholds. But as he came to a sharp break in the side of the mountain, the lofty pointed crag shaped up straighter and more jagged. Once he thought he had gone as far as possible, but finally managed to get to the brink of a slab that had threatened to hinder his progress.
“On to the top,” he thought, bringing his foot up another notch with difficulty.
At last, panting and perspiring, he ascended the last stretch and took his position on the flat surface of a platform-like formation. Then he turned to look below.
A cry of astonishment came from his lips as he saw that he was hundreds and hundreds of feet in the air. Far, far below, he could dimly make out his dromedary by the outermost side of the mountain. The beast seemed no larger than an ant.
“I wonder if Dad and the others can be seen,”he mused, turning his gaze in the opposite direction.
“Yes!” he muttered excitedly. “There they are.”
He had caught sight of his father and friends being led up the valley by their Arab captors. The camels on which they rode seemed only crawling, so small did they appear.
As usual, his binoculars were strapped over his shoulder, and he took them out to get a closer view. Through them he could see the worried expressions on his friends’ faces, and the surly grins of the Arabs.
There was a sort of narrow ledge that passed up the little valley and around the mountain. It was up this that the captives were being led.
“There’s probably a hideout somewhere around here,” the youth thought, shifting his eyes from the camel procession to the rugged country ahead.
From his lofty perch it might be possible to get a glimpse of the hidden cave in which were the riches. Bob scanned the landscape about him but finally gave up and again followed the movements of his friends and the Arabs.
“If it’s anywhere around here, it’s concealed from view,” he thought.
The youth was crouching low behind a flat shelf of rock, so as to be invisible to the Arabs if they should happen to look up in that direction. He knew that their seeing him would spell his doom.
As Bob watched the line of camels and their riders, it seemed that they were making no time at all; yet he knew that they were winding around the mountain as fast as possible.
Up, up, up they went, but always in sight. Bob noticed that they were gradually moving away from him, and he wondered if he would be able to follow their movements to the end.
“If I can’t, I’ll have to change peaks,” he thought, although he realized that this would be difficult and dangerous.
The Arabs and their captives were now nearing a high wall of rock that would prevent them from being seen. But it would be for only a short time—if they did not stop opposite it.
After what seemed like hours to Bob, they emerged again into view, this time at the brink of a high cliff.
“Hope they don’t step off of there,” the youth breathed, his heart in his mouth.
At last, just as the sun was beginning to sink behind the distant peaks, the camels and their riders came to a stop at an opening in a mountainside that evidently led into a cave.
Hardly able to hold the binoculars steady, Bob watched breathlessly, almost expecting to catch sight of Joe and Dr. Kirshner. But those individuals did not make an appearance. Bob did not doubt, however, that they were in the cave.
A moment later, captors and captives dismounted from their dromedaries and walked through the opening out of sight.
Bob waited silently for another half-hour, thinking that it might be possible that this was only a temporary prison. But when at the end of that time no one had left the cave, he was convinced that this was a permanent hideout.
“Now I suppose it’s up to me to get down from here right away,” Bob thought, gliding silently off the shelf and onto a narrow ridge that was directly below.
Carefully he felt his way down with great difficulty. As he had surmised, the descent would prove much harder than the ascent.
Once his heart sank, as he saw that a five-foot wall of stone was directly below him. But then he suddenly remembered that a little to his right there were protruding rocks that would offer footholds. He edged around, and in a short time was again climbing steadily down.
The minutes passed. When he was a third of the way to the bottom, darkness began to fall rapidly. He realized that he could not get to the base of the peak before pitch darkness would envelop him.
“But I’ve got to keep going down,” he told himself, frantically feeling his way among the rocks.
For the past five minutes he had been getting drowsy, sleepy. The day’s strain was beginning totell on him. With an effort he kept himself awake. He knew the grim consequences if he should suddenly fall asleep while making the dangerous descent of the peak.
He was half of the way down; now two thirds. But a few more hundred feet remained, and he braced himself and continued his slow, careful movement.
“Not much more now,” he observed, glancing down. “Ought to make it in a few more minutes.”
Long before, darkness had come upon him, making the frequent use of his small flashlight necessary. Even then it was a hard task.
“Must be almost to the bottom,” he thought, when another fifteen minutes had passed.
He flashed the light downward and saw that fifty feet still remained. Again he bent his efforts upon the descent that was still before him, and in no time had covered most of the distance.
But just when he prepared to use his flashlight, a small rock gave way from under his left foot. He tried vainly to catch hold of a sharp crag, and then felt himself falling!
WHENBob reached the ground, he was sore from numerous bruises, but to his great joy his legs and arms responded to his efforts to move them.
He glanced up the side of the peak, but the darkness veiled his vision.
“Wonder what became of the old flashlight?” he mused, feeling about on the soft ground.
Finally his hand came upon something hard, and a thrill of delight ran through him as he realized that he had found the electric torch. But his heart sank as he saw that it had been damaged by the fall.
“Lens wasn’t broken, though,” he observed. “Must be the bulb.”
Without the light there was no way of knowing how far he had fallen. But he readily guessed that it was not over eight or nine feet.
The moon was just beginning to show itself from behind the thin clouds, and it might be possible to travel in its light. Whether to do so or not, Bob could not easily decide. He knew that Fekmahwould be extremely worried if no one returned to camp that night, but he doubted if he could keep awake long enough to direct his dromedary over the right way. He finally made up his mind to stretch out beside the mountain and surrender himself over to sleep.
“I hate to treat Fekmah that way, but I don’t believe I could make it back,” the youth thought, closing his eyes.
A second later he fell asleep, not to awaken until the sun was well up in the sky.
“Eight o’clock!” he cried, looking at his watch. “By George! I bet Fekmah is throwing a dozen fits.”
Bob at once jumped up and untied his dromedary. He was on the animal in a moment and rode back toward camp.
“I hope I know the way,” he thought, as he was carried to the spot where his father, Mr. Lewis, and Tishmak had been captured.
But the youth had carefully observed the landmarks as they left camp on the search, and had no difficulty in recognizing the way.
First, however, Bob had made a small sketch map of the distant cave in which his father and friend were being held captive. He was positive he could locate it, perhaps without the use of the map.
Bob was now passing up the path that Tishmakhad believed made by Tuaregs. For a good distance it would be necessary to follow this lane; then he would turn off on a level stretch.
Suddenly, as Bob made a sharp bend in the path, his jaw fell in surprise and horror.
Not twenty feet away sat a native, a Tuareg, with his back against a low rock. The man was terror-stricken as he watched a long reptile move toward him with a slow, terrible fascination.
That the man knew not what to do, Bob rightly guessed. If he should make the slightest move, the reptile, a deadly horned viper, would strike.
“It’s up to me to come to his rescue,” thought Bob, and, raising his rifle, he took steady aim.
The report of the gun was followed by a terrible twitching of the snake. Meanwhile the Tuareg had jumped in surprise at the sound of the gun and was now looking at his benefactor thankfully.
Bob rode on up to the man and dismounted, to be met by the Tuareg. The latter was of unusual height, towering several inches above Bob, who was himself six feet.
The man quite promptly threw his arms around Bob and hugged him, too thankful for words that he had escaped a terrible death. It was rather embarrassing for the young American, but he smiled modestly and passed the thanks aside as best he could.
Finally the Tuareg stood away and motioned forBob to follow him up the path. The youth did as directed, even though he was anxious about getting back to camp.
As Bob followed his newly made friend up the lane, he took note of the man’s dress. He was garbed in a loose black robe, which reached almost to his feet. On his chest were numerous decorations that distinguished him as a man of some importance among his people. What seemed most unusual was a black veil that covered his face, leaving little more than his eyes visible. On his head was a strange high cap of black and white.
“Quite a specimen,” thought Bob. “And evidently a chief or nobleman.”
Ten minutes of walking brought them to the top of the hill. Then, as they moved around a large rock, Bob caught sight of several tents placed about a hundred yards apart on a vast plain.
Several natives came running out, followed by a score more. They rushed forward as they caught sight of Bob and his friend.
The latter at once spoke excitedly to his fellow people, and Bob rightly guessed that he was telling of being saved from the snake by the white youth.
When the man had finished, the Tuaregs looked at Bob with gratitude and admiration. They asked him by signs to come into their tent village, and he did so.
“Wish I could speak some of their language,” he thought, as he was being shown the various things about the tents.
It now became apparent that the man whom Bob had saved from death was the chieftain of the tribe, as he was held in high esteem by all. And no one else wore such decorations as did he.
Suddenly a thought struck Bob, and he smiled in renewed hope. Perhaps it would be possible to engage the aid of these Tuaregs in rescuing his friends from the Arabs. Could it be worked?
Bob was now extremely anxious to get back to camp, for he knew that Dr. Kirshner had prepared a paper with many Tuareg words on it for reference. The youth would get that paper and then come back and ask for help in rescuing his father and the others. Perhaps they would be willing to give aid.
As best he could, Bob told the Tuaregs by signs that he must be leaving, and it was evident that they understood. With a last farewell, the youth turned his dromedary away.
His hopes were high as he rapidly covered ground toward camp. Before coming across these Tuaregs, Bob was in doubt as to whether he could tackle so many of the Arabs alone in order to rescue his father and friends. Now, with the prospects of getting aid from the Tuaregs, the future looked brighter.
“Still they might not be willing to help,” he thought. “But at least I can ask them.”
After winding in and out among the huge rocks and peaks for well over an hour, Bob turned his camel up a little hill and came in sight of camp.
How good it looked! Since his friends had been captured by the Arabs, the youth had had an uneasy feeling that perhaps he could not find his way back.
“Where’s Fekmah, I wonder,” he mused, looking about.
A moment later the Arab came running up, delighted beyond words at again seeing him alive and well.
“What kept you away so long?” Fekmah asked. “And where are the others?”
Bob’s face darkened. He told of his father, Mr. Lewis, and Tishmak being captured by the Arabs, and of his own good fortune in getting away.
“But,” he said, “I have a plan to bring about their rescue.”
“What is it?” Fekmah waited breathlessly.
“On the way back to camp this morning, I came upon some Tuaregs who live in a tent village several miles from here. They were very friendly and wanted me to stay longer, but I told them I had to get back.
“Now Dr. Kirshner has a paper with a good many Tuareg words on it. I remember hearing himtell about it several days ago. If we can find that, everything will probably be all right. We’ll take it with us to their village and ask them in their own language to help us. How does it sound?”
“Very good,” Fekmah returned. “But do you think they will?”
“Won’t do any harm to find out,” Bob said, going in the tent.
Dr. Kirshner’s large satchel was on a box, and the young man at once took it down and searched its contents for the paper of Tuareg words. His nerves were on edge with a terrible fear that perhaps it would not be there.
Papers and books and pamphlets were all taken out and hastily read. Scarcely would the youth glance at one sheet when he would pick up another. Under ordinary circumstances, Dr. Kirshner would not have permitted anyone to go through his belongings, but now it was a case of necessity.
Suddenly Bob straightened up in great relief. He had at last found the object of his search.
“Here it is,” he said to Fekmah, who was standing beside him. “A translation of about three hundred Tuareg words. Now I guess we’ll fool those Arab crooks.”
Bob had had nothing to eat that morning, and he was very hungry. He lost no time in preparinga satisfying breakfast. When he had finished eating, he turned to Fekmah.
“Now,” he said, “I’m going to that Tuareg village and ask for aid in rescuing Dad and the others. You had better stay here with the camels and supplies, hadn’t you? It would probably mean tragedy for us if anything should happen to them.”
“Yes,” the Arab returned, “I will stay. And I not afraid that you will fail.”
“I’ll try not to,” Bob said, getting on his dromedary.
With a warm farewell the youth rode off at a rapid pace. His mind was desperately set upon a purpose. He would rescue his father and friends if he had to do it himself.
The Tuareg village was several miles away, but his fleet-footed camel covered the distance in no time.
“Here’s where I get busy with this new dialect,” Bob thought, getting out the paper of native words.
A score or more Tuaregs came running up, led by the chieftain, whom Bob had saved from death previously. The people shouted sincere welcomes.
Bob glanced down at the paper and found a few words for casual conversation. They were not difficult to pronounce, and the effect upon the natives was astounding. They were indeed surprised to find that this white youth could speak any of their language.
But before long Bob got to the purpose. There was one word that stood out in his mind more prominently than any of the others. It wasreeskra(help).
As best he could, the young American picked out several words and put them in sentences. He outlined briefly and simply that his father and friends were being held captives in a cave not a great distance away. If the Tuaregs would give aid, they would be rewarded. Would they help?
The result of his request was instantaneous. The Tuareg men, nearly all six-footers, waved their guns in the air and commanded Bob to lead them to the cave where the whites were being guarded.
A thrill of joy ran through Bob’s veins, and he ordered his dromedary to move forward. At last his father and friends would be released.
FORa distance of several hundred yards the country remained comparatively level, although dotted with huge rocks. Then mountains loomed up before them, and they found it necessary to travel slower.
Bob was followed by about fifteen Tuareg warriors, all magnificent specimens of “desert knights.” Each man was armed with a rifle which, although inferior to Bob’s high-velocity type, could do much damage.
Bob was almost certain he could find the way without the small sketch map he had made from the top of the tall peak the night before. But he had the map in his pocket and intended to consult it if necessary.
Breathlessly he led the way through the rough country and at last came to the spot where his father and friends had been captured by the Arabs.
From then on, finding the way would be easy, the youth thought, for he had only to move toward an odd formation of twin peaks that loomed upabove the other mountains in the distance. The cave in which those captured were probably being held was along the side of those tall double peaks.
To make sure of this, Bob got out the map and scrutinized it closely. Then, satisfied that he was right, he dashed forward, the Tuaregs at his heels.
The way now led up the side of a large hill. There was a break just to one side of the path, and the rescuers could look down to the foot of a deep gorge. Bob kept his dromedary as far away from the brink as possible, to do away with the grim possibility of the ground giving way from under his camel’s feet.
Finally, after trudging over a high plateau, they began climbing the base of the twin peaks. At first the ascent was very gradual, but in a short time the path curved upward around the side of the mountain.
“Getting there, all right,” observed Bob, as he noticed that they were now several hundred feet above the plateau.
At last they came to the top of a wide ledge, from which they could look out over scores of miles of rugged country. As the shelf began to narrow, Bob called a halt.
He took out the paper of native words and told the Tuaregs that they were now near the cave in which were his father and friends. It would onlybe necessary to round a corner before coming to its entrance.
But first he divided the group of natives into two sections. One, under the command of the chieftain, was to move on around the ledge to the cave from the west. The other, led by himself, would climb the steep side of the mountain and walk on above to the other side of the cavern. Then they would meet at the entrance and surround the Arabs and release the prisoners.
When Bob gave the word, the Tuaregs swung into action. Those in his group followed him up the cliff to the brink, while the men under the chieftain began moving around the ledge.
It was a dangerous climb up the steep side of the mountain, but at last Bob pulled himself up to another ledge about fifty feet above the lower one. Then he led the way several rods along its surface. When he thought they had passed beyond the entrance to the cave, he led the descent to the lower shelf.
A moment later he saw that he had miscalculated. He had not gone far enough beyond the cavern to escape the wary eyes of the Arabs who were stationed as guards.
“Caught!” he exclaimed. “Caught square!”
Four Arabs were sitting out in front, and they were on their feet instantly as their eyes fell on Bob. The latter was no more than twenty-five feetaway from them, much nearer than he had expected to be.
The Arabs’ rifles were standing against the wall of rock near the cave. But before the men could get to them, Bob rushed forward. With a wild shout he kicked the rifles away and dashed into the cavern.
Startled exclamations—exclamations of joy, surprise, happiness—came to the youth’s ears, and he realized that he had at last found his father, Joe, and the others.
“Bob! You here!” cried Mr. Holton in wild excitement.
“You old rascal! I knew you’d get us out!” came from Dr. Kirshner.
But there was no time for that. Danger was at hand.
“Quick!” he commanded. “Hide. Here, take my rifle, somebody. I’ll use my pistol. There’s no time to lose!”
The words were scarcely out of his mouth when the four Arabs darted inside the cave and made for the captives and their new enemy. They would not be beaten so easily!
With a terrific crack to the chin, Bob sent the foremost Arab to the ground. The other three men were making for the prisoners in the back of the cave.
Mr. Holton had taken Bob’s rifle and was by the youth’s side looking for other Arabs.
Suddenly Bob noticed that the man whom he had knocked down was getting to his feet and making for the rifles not far away.
Without hesitating a moment, the youth dashed out of the cave and directed a stinging blow to the Arab’s nose. The latter staggered a moment at the edge of the cliff, and then, to the horror of the two Americans, fell backwards over the cliff.
Bob gave a cry of regret. Despite the fact that the Arab was an enemy, the young man did not wish to send him to his death.
Mr. Holton had also been touched deeply.
“You—you shouldn’t have done that,” he muttered. “But—it couldn’t have been helped.”
Now a chorus of shouts and yells rent the air, and the Tuaregs rushed into the cave. To the surprise and relief of the Americans, they had captured the two thieves who stole Fekmah’s map. Where had they found them?
Mr. Holton, Dr. Kirshner, and the other former prisoners were taken aback at sight of the natives. At first they thought them other enemies. Bob soon gave an explanation.
The thieves were searched for Fekmah’s map, but the latter was not found.
Meanwhile a struggle was taking place at the rear of the cave.
Joe in particular attracted Bob’s attention. The former youth was grappling with a large, powerful fellow, who was vainly trying to choke his young enemy.
“Joe’s sure a fighter,” remarked Bob, as he and his father looked on for a moment.
“We had better help him, though,” Mr. Holton said. “Come on.”
But a second later they saw that this would be unnecessary, for Joe had suddenly jerked away and sent his fist with all force into the Arab’s jaw, knocking him out.
“Great work!” commended Mr. Holton. “That fellow was dangerous.”
The two remaining Arabs saw that they had no chance against so many, and they surrendered without a struggle.
“Now tell us all about it,” urged Dr. Kirshner, speaking to Bob. “We want to know how you managed to engage the aid of these Tuaregs.”
Briefly the youth outlined his adventures since escaping from the Arabs the day before. He told of climbing to the top of the peak, of saving the Tuareg chieftain from death, and of getting the paper of Tuareg words.
“That’s all,” he finished. “Only these natives came up here with me to get you out of the clutches of these Arabs.”
“A wonderful demonstration of ingenuity,”breathed Mr. Lewis. “We expected you all the time. Knew you’d find some way.”
“But our greatest work is yet before us,” Bob said. “We must drive the Arabs from the hidden treasure—if we can locate it.”
“No,” came from Mr. Holton, “we won’t need to do that.”
BOBlooked at his father in surprise.
“What do you mean?” he asked.
“Simply that no one is there to drive away now,” was the reply. “We have captured all of the Arabs—even the two thieves who stole Fekmah’s map. And I might add that we have located the hidden treasure.”
“What! You’ve been there?”
“No, but we’ve seen the cave in which it is. In fact, it is possible to see it from here.”
Mr. Holton took out his binoculars and handed them to his son.
“Look away over there,” the naturalist said, pointing to a distant wall of rock that was many hundred feet high. “That small shelf on the side of the cliff is an opening into the cave in which are the hidden riches.”
Bob scanned the landscape ahead. Then he cried out in surprise and amazement.
“A cave away up in that cliff? Seems impossible. How can you get to it?”
“Must be an entrance on the other side,” Dr. Kirshner replied. “Fekmah’s map no doubt points it out. Whether he remembered to put it on the duplicate after the original was stolen, we have yet to see. Where is he now?”
“Who, Fekmah? I left him at camp this morning.”
“Let’s go there now.”
First, however, Dr. Kirshner engaged in conversation with the Tuaregs in their own language. He told them, among other things, of how grateful he and the other former prisoners were for their help in releasing them from the clutches of the Arabs.
The natives were very courteous and friendly, inviting the archæologist to their village. He returned that he would be delighted to visit them, and concluded by saying that they would be given a reward for their generous services.
“Now let’s get out of here,” he said, turning to his friends. “I’m particularly anxious to get back to camp and see Fekmah. I wonder if any misfortune could have come upon him and our camels.”
The Americans, Tuaregs, and Arab captives left the cave behind and trudged down the mountainside. But before they did so, they carried out the food supply that had been in the cave for the prisoners and their guards. It consisted of simplenative food, but was welcomed by the Americans and Tishmak.
“There is much more in the cave where the hidden treasure is,” remarked Joe, as he walked beside his chum, who was leading his camel. “We won’t need to worry about not having enough to eat for many weeks.”
“Doubt if we’ll stay here that much longer,” Bob said. “But I imagine it’ll come in handy all right.”
The Arabs were ordered to walk in front of the Americans and Tishmak. The Tuaregs rode on to their village, after asking their newly made friends to visit them the next morning.
It required several hours for the explorers and their captives to get back to camp, going on foot as they did. But when they finally came within sight of the tent and camels, all gave sighs of relief.
Fekmah came running out to meet them, his face showing an intense thankfulness at again seeing his American friends and Tishmak alive and apparently none the worse for their experience.
“So Bob got you from Arab demons,” he muttered and then added: “I knew he would do it.”
Nothing would satisfy him but a complete detailed account of their experiences, and it was Mr. Lewis who related all of the happenings since they had last left camp.
“Howard [Mr. Holton] and Tishmak and I were sure greatly relieved when our captors took us to the cave where Joe and Dr. Kirshner were being held,” Mr. Lewis finished. “Funny, but we had not dreamed of them being prisoners.”
“And I see you’ve brought the rascals with you,” observed Fekmah. “What are we going to do with them?”
“I’m sure we’ve all been thinking about that,” Dr. Kirshner returned. “There are no police so far south as this, and we can’t very well take them with us back to Wargla. I wonder how it would be to take them to an oasis fifty miles or so from here and leave them? There would be no danger of them starving, because dates and water would furnish food. And they couldn’t get away without camels.”
“Sounds all right,” Mr. Holton said. “Do you know where there is such an oasis?”
“No, but I’m sure our Tuareg friends do. I’ll ask them in the morning. Until then we’ll have to keep our eyes on these Arabs. It might be well to tie them up.”
This was thought good advice, and the captives were bound together so tightly that they could not escape.
The remainder of that day passed idly, and the explorers retired shortly after the evening meal.
“But we must be up early in the morning,” Mr.Holton told them. “We have a big day before us.”
They all slept the sleep of exhaustion and did not awaken as early as they had intended.
Breakfast over, Dr. Kirshner and Bob got on their camels and started for the Tuareg village. The others put in a request to go also, but the archæologist stoutly refused, saying that no time must be wasted.
“We only want to make arrangements to take these Arab crooks to an oasis and leave them,” he said. “If more of you go, it will necessarily keep us longer.”
It did not take the two long to get to the natives’ village. The chieftain at once came out to meet the newcomers, and Bob introduced Dr. Kirshner to them.
After a few casual remarks the scientist got to the point. He told the natives of his desire to banish the Arabs to an oasis, if any were near. He also asked if enough camels could be borrowed to take the crooks there.
The chieftain at once replied that he knew of an oasis a half-day’s journey from the village, and that he would gladly let them have the camels.
“Fine!” Dr. Kirshner said in the native tongue. “We’ll go there at once.”
The chieftain insisted upon leading them to the oasis, for, he said, they could not find it alone.
Dr. Kirshner consented, and the head native atonce herded enough camels to take the prisoners away. Then the Americans and the Tuareg chieftain started for the explorers’ camp to get the Arabs.
“Be glad when this job’s over,” remarked Bob, as they rode toward camp. “I’m anxious to see the hidden treasure.”
They arrived at camp and placed each Arab on a dromedary. After preparing a lunch to last them until they would return, Dr. Kirshner, Bob, and the Tuareg chieftain began the journey to the oasis, riding behind the prisoners and guarding them closely.
The oasis was about forty miles away, situated on a barren sand plain surrounded by mountains. The Tuareg explained that there was no other well near and that the prisoners would be forced to stay there for an indefinite period, for no caravans passed along that way.
In order to get to the place it was necessary to go through the mountains, and traveling was not any too easy. But they rode with a determination and finally arrived at the oasis.
The Arabs were commanded to dismount and walk forward. Then, after filling their canteens with water, the Americans and the Tuaregs started the return journey, herding the dromedaries ahead of them.
“Now that that’s over, maybe we can rest easy,”said Dr. Kirshner. “Those Arabs can’t get away because of not having camels, and the monotony will punish them greatly.”
Bob, the scientist, and the Tuareg made good time that afternoon, arriving at the explorers’ camp just before sundown. The chieftain lost no time in getting back to his village, after being thanked warmly for his services.
“We’ll see that those Tuaregs get a reward,” said Mr. Holton. “Just as soon as we get to the hidden treasure we’ll give it to them.”
The natives had not been told of the cave of riches, however, for fear that their age-old desire to raid might get the better of them.
Very early the next morning the explorers got their belongings placed on the dromedaries and started out for the cave of treasure. Although it would mean only a few hours’ journey, they were extremely impatient.
“Wonder if those Arabs carried any of the riches away?” asked Bob, as they rode toward the high wall of rock, in the side of which was the cave.
“No,” Mr. Holton returned. “They hadn’t started yet. Were just looking over everything. At least that’s what our guards told us. It seemed that they intended to carry the stuff out in a day or two.”
“Wanted to catalog everything first, huh?” askedBob. “Well, it’s a good thing we stopped them when we did.”
Fekmah found it necessary to consult his duplicate map very frequently, and he wondered if he had remembered to put in all the details accurately.
Finally, after they had passed the tall wall of rock and were following a narrow trail up the mountain on the opposite side of the cliff, Dr. Kirshner turned to Bob.
“You asked the other day how we were to get into the cave,” he said. “Of course it would be impossible to scale that lofty cliff. Fekmah’s map points out a narrow opening in the rock somewhere in this vicinity, and we ought to find it in a very few minutes now.”
He had scarcely uttered the words when Fekmah cried out in delight and pointed to a peculiar rock formation not far ahead.
“There it is,” he declared joyfully. “There is where we enter mountain to get cave of treasure.”
The explorers, led by Fekmah, moved on up to the spot.
“Here’s an opening!” cried Joe, pointing to a small crack that was barely large enough to let them in.
Getting out their flashlights, they followed Fekmah through the crack and into a narrow tunnel. The air was damp and heavy from the breath of ages, but they trudged on through.
After what seemed like hours, the passageway gradually became lighter, and the explorers found themselves in a large cave.
Suddenly Joe stumbled and fell, unable to catch himself.
“What’s this!” he mumbled.
Then, as his light was turned to the floor, he gave an exclamation of joy.
“The hidden riches!” he said excitedly. “I’ve found them!”