Tarzan's first mission did not bid fair to be either exciting or vastly important. There was a certain lieutenant of Spahis whom the government had reason to suspect of improper relations with a great European power. This Lieutenant Gernois, who was at present stationed at Sidibel-Abbes, had recently been attached to the general staff, where certain information of great military value had come into his possession in the ordinary routine of his duties. It was this information which the government suspected the great power was bartering for with the officer.

It was at most but a vague hint dropped by a certain notorious Parisienne in a jealous mood that had caused suspicion to rest upon the lieutenant. But general staffs are jealous of their secrets, and treason so serious a thing that even a hint of it may not be safely neglected. And so it was that Tarzan had come to Algeria in the guise of an American hunter and traveler to keep a close eye upon Lieutenant Gernois.

He had looked forward with keen delight to again seeing his beloved Africa, but this northern aspect of it was so different from his tropical jungle home that he might as well have been back in Paris for all the heart thrills of homecoming that he experienced. At Oran he spent a day wandering through the narrow, crooked alleys of the Arab quarter enjoying the strange, new sights. The next day found him at Sidi-bel-Abbes, where he presented his letters of introduction to both civil and military authorities — letters which gave no clew to the real significance of his mission.

Tarzan possessed a sufficient command of English to enable him to pass among Arabs and Frenchmen as an American, and that was all that was required of it. When he met an Englishman he spoke French in order that he might not betray himself, but occasionally talked in English to foreigners who understood that tongue, but could not note the slight imperfections of accent and pronunciation that were his.

Here he became acquainted with many of the French officers, and soon became a favorite among them. He met Gernois, whom he found to be a taciturn, dyspeptic-looking man of about forty, having little or no social intercourse with his fellows.

For a month nothing of moment occurred. Gernois apparently had no visitors, nor did he on his occasional visits to the town hold communication with any who might even by the wildest flight of imagination be construed into secret agents of a foreign power. Tarzan was beginning to hope that, after all, the rumor might have been false, when suddenly Gernois was ordered to Bou Saada in the Petit Sahara far to the south.

A company of Spahis and three officers were to relieve another company already stationed there. Fortunately one of the officers, Captain Gerard, had become an excellent friend of Tarzan's, and so when the ape-man suggested that he should embrace the opportunity of accompanying him to Bou Saada, where he expected to find hunting, it caused not the slightest suspicion.

At Bouira the detachment detrained, and the balance of the journey was made in the saddle. As Tarzan was dickering at Bouira for a mount he caught a brief glimpse of a man in European clothes eying him from the doorway of a native coffeehouse, but as Tarzan looked the man turned and entered the little, low-ceilinged mud hut, and but for a haunting impression that there had been something familiar about the face or figure of the fellow, Tarzan gave the matter no further thought.

The march to Aumale was fatiguing to Tarzan, whose equestrian experiences hitherto had been confined to a course of riding lessons in a Parisian academy, and so it was that he quickly sought the comforts of a bed in the Hotel Grossat, while the officers and troops took up their quarters at the military post.

Although Tarzan was called early the following morning, the company of Spahis was on the march before he had finished his breakfast. He was hurrying through his meal that the soldiers might not get too far in advance of him when he glanced through the door connecting the dining room with the bar.

To his surprise, he saw Gernois standing there in conversation with the very stranger he had seen in the coffee-house at Bouira the day previous. He could not be mistaken, for there was the same strangely familiar attitude and figure, though the man's back was toward him.

As his eyes lingered on the two, Gernois looked up and caught the intent expression on Tarzan's face. The stranger was talking in a low whisper at the time, but the French officer immediately interrupted him, and the two at once turned away and passed out of the range of Tarzan's vision.

This was the first suspicious occurrence that Tarzan had ever witnessed in connection with Gernois' actions, but he was positive that the men had left the barroom solely because Gernois had caught Tarzan's eyes upon them; then there was the persistent impression of familiarity about the stranger to further augment the ape-man's belief that here at length was something which would bear watching.

A moment later Tarzan entered the barroom, but the men had left, nor did he see aught of them in the street beyond, though he found a pretext to ride to various shops before he set out after the column which had now considerable start of him. He did not overtake them until he reached Sidi Aissa shortly after noon, where the soldiers had halted for an hour's rest. Here he found Gernois with the column, but there was no sign of the stranger.

It was market day at Sidi Aissa, and the numberless caravans of camels coming in from the desert, and the crowds of bickering Arabs in the market place, filled Tarzan with a consuming desire to remain for a day that he might see more of these sons of the desert. Thus it was that the company of Spahis marched on that afternoon toward Bou Saada without him. He spent the hours until dark wandering about the market in company with a youthful Arab, one Abdul, who had been recommended to him by the innkeeper as a trustworthy servant and interpreter.

Here Tarzan purchased a better mount than the one he had selected at Bouira, and, entering into conversation with the stately Arab to whom the animal had belonged, learned that the seller was Kadour ben Saden, sheik of a desert tribe far south of Djelfa. Through Abdul, Tarzan invited his new acquaintance to dine with him. As the three were making their way through the crowds of marketers, camels, donkeys, and horses that filled the market place with a confusing babel of sounds, Abdul plucked at Tarzan's sleeve.

"Look, master, behind us," and he turned, pointing at a figure which disappeared behind a camel as Tarzan turned. "He has been following us about all afternoon," continued Abdul.

"I caught only a glimpse of an Arab in a dark-blue burnoose and white turban," replied Tarzan. "Is it he you mean?"

"Yes. I suspected him because he seems a stranger here, without other business than following us, which is not the way of the Arab who is honest, and also because he keeps the lower part of his face hidden, only his eyes showing. He must be a bad man, or he would have honest business of his own to occupy his time."

"He is on the wrong scent then, Abdul," replied Tarzan, "for no one here can have any grievance against me. This is my first visit to your country, and none knows me. He will soon discover his error, and cease to follow us."

"Unless he be bent on robbery," returned Abdul.

"Then all we can do is wait until he is ready to try his hand upon us," laughed Tarzan, "and I warrant that he will get his bellyful of robbing now that we are prepared for him," and so he dismissed the subject from his mind, though he was destined to recall it before many hours through a most unlooked-for occurrence.

Kadour ben Saden, having dined well, prepared to take leave of his host. With dignified protestations of friendship, he invited Tarzan to visit him in his wild domain, where the antelope, the stag, the boar, the panther, and the lion might still be found in sufficient numbers to tempt an ardent huntsman.

On his departure the ape-man, with Abdul, wandered again into the streets of Sidi Aissa, where he was soon attracted by the wild din of sound coming from the open doorway of one of the numerous cafes maures. It was after eight, and the dancing was in full swing as Tarzan entered. The room was filled to repletion with Arabs. All were smoking, and drinking their thick, hot coffee.

Tarzan and Abdul found seats near the center of the room, though the terrific noise produced by the musicians upon their Arab drums and pipes would have rendered a seat farther from them more acceptable to the quiet-loving ape-man. A rather good-looking Ouled-Nail was dancing, and, perceiving Tarzan's European clothes, and scenting a generous gratuity, she threw her silken handkerchief upon his shoulder, to be rewarded with a franc.

When her place upon the floor had been taken by another the bright-eyed Abdul saw her in conversation with two Arabs at the far side of the room, near a side door that let upon an inner court, around the gallery of which were the rooms occupied by the girls who danced in this cafe.

At first he thought nothing of the matter, but presently he noticed from the corner of his eye one of the men nod in their direction, and the girl turn and shoot a furtive glance at Tarzan. Then the Arabs melted through the doorway into the darkness of the court.

When it came again the girl's turn to dance she hovered close to Tarzan, and for the ape-man alone were her sweetest smiles. Many an ugly scowl was cast upon the tall European by swarthy, dark-eyed sons of the desert, but neither smiles nor scowls produced any outwardly visible effect upon him. Again the girl cast her handkerchief upon his shoulder, and again was she rewarded with a franc piece. As she was sticking it upon her forehead, after the custom of her kind, she bent low toward Tarzan, whispering a quick word in his ear.

"There are two without in the court," she said quickly, in broken French, "who would harm m'sieur. At first I promised to lure you to them, but you have been kind, and I cannot do it. Go quickly, before they find that I have failed them. I think that they are very bad men."

Tarzan thanked the girl, assuring her that he would be careful, and, having finished her dance, she crossed to the little doorway and went out into the court. But Tarzan did not leave the cafe as she had urged.

For another half hour nothing unusual occurred, then a surly-looking Arab entered the cafe from the street. He stood near Tarzan, where he deliberately made insulting remarks about the European, but as they were in his native tongue Tarzan was entirely innocent of their purport until Abdul took it upon himself to enlighten him.

"This fellow is looking for trouble," warned Abdul. "He is not alone. In fact, in case of a disturbance, nearly every man here would be against you. It would be better to leave quietly, master."

"Ask the fellow what he wants," commanded Tarzan.

"He says that 'the dog of a Christian' insulted the Ouled-Nail, who belongs to him. He means trouble, m'sieur."

"Tell him that I did not insult his or any other Ouled-Nail, that I wish him to go away and leave me alone. That I have no quarrel with him, nor has he any with me."

"He says," replied Abdul, after delivering this message to the Arab, "that besides being a dog yourself that you are the son of one, and that your grandmother was a hyena. Incidentally you are a liar."

The attention of those near by had now been attracted by the altercation, and the sneering laughs that followed this torrent of invective easily indicated the trend of the sympathies of the majority of the audience.

Tarzan did not like being laughed at, neither did he relish the terms applied to him by the Arab, but he showed no sign of anger as he arose from his seat upon the bench. A half smile played about his lips, but of a sudden a mighty fist shot into the face of the scowling Arab, and back of it were the terrible muscles of the ape-man.

At the instant that the man fell a half dozen fierce plainsmen sprang into the room from where they had apparently been waiting for their cue in the street before the cafe. With cries of "Kill the unbeliever!" and "Down with the dog of a Christian!" they made straight for Tarzan. A number of the younger Arabs in the audience sprang to their feet to join in the assault upon the unarmed white man. Tarzan and Abdul were rushed back toward the end of the room by the very force of numbers opposing them. The young Arab remained loyal to his master, and with drawn knife fought at his side.

With tremendous blows the ape-man felled all who came within reach of his powerful hands. He fought quietly and without a word, upon his lips the same half smile they had worn as he rose to strike down the man who had insulted him. It seemed impossible that either he or Abdul could survive the sea of wicked-looking swords and knives that surrounded them, but the very numbers of their assailants proved the best bulwark of their safety. So closely packed was the howling, cursing mob that no weapon could be wielded to advantage, and none of the Arabs dared use a firearm for fear of wounding one of his compatriots.

Finally Tarzan succeeded in seizing one of the most persistent of his attackers. With a quick wrench he disarmed the fellow, and then, holding him before them as a shield, he backed slowly beside Abdul toward the little door which led into the inner courtyard. At the threshold he paused for an instant, and, lifting the struggling Arab above his head, hurled him, as though from a catapult, full in the faces of his on-pressing fellows.

Then Tarzan and Abdul stepped into the semidarkness of the court. The frightened Ouled-Nails were crouching at the tops of the stairs which led to their respective rooms, the only light in the courtyard coming from the sickly candles which each girl had stuck with its own grease to the woodwork of her door-frame, the better to display her charms to those who might happen to traverse the dark inclosure.

Scarcely had Tarzan and Abdul emerged from the room ere a revolver spoke close at their backs from the shadows beneath one of the stairways, and as they turned to meet this new antagonist, two muffled figures sprang toward them, firing as they came. Tarzan leaped to meet these two new assailants. The foremost lay, a second later, in the trampled dirt of the court, disarmed and groaning from a broken wrist. Abdul's knife found the vitals of the second in the instant that the fellow's revolver missed fire as he held it to the faithful Arab's forehead.

The maddened horde within the cafe were now rushing out in pursuit of their quarry. The Ouled-Nails had extinguished their candles at a cry from one of their number, and the only light within the yard came feebly from the open and half-blocked door of the cafe. Tarzan had seized a sword from the man who had fallen before Abdul's knife, and now he stood waiting for the rush of men that was coming in search of them through the darkness.

Suddenly he felt a light hand upon his shoulder from behind, and a woman's voice whispering, "Quick, m'sieur; this way. Follow me."

"Come, Abdul," said Tarzan, in a low tone, to the youth; "we can be no worse off elsewhere than we are here."

The woman turned and led them up the narrow stairway that ended at the door of her quarters. Tarzan was close beside her. He saw the gold and silver bracelets upon her bare arms, the strings of gold coin that depended from her hair ornaments, and the gorgeous colors of her dress. He saw that she was a Ouled-Nail, and instinctively he knew that she was the same who had whispered the warning in his ear earlier in the evening.

As they reached the top of the stairs they could hear the angry crowd searching the yard beneath.

"Soon they will search here," whispered the girl. "They must not find you, for, though you fight with the strength of many men, they will kill you in the end. Hasten; you can drop from the farther window of my room to the street beyond. Before they discover that you are no longer in the court of the buildings you will be safe within the hotel."

But even as she spoke, several men had started up the stairway at the head of which they stood. There was a sudden cry from one of the searchers. They had been discovered. Quickly the crowd rushed for the stairway. The foremost assailant leaped quickly upward, but at the top he met the sudden sword that he had not expected — the quarry had been unarmed before.

With a cry, the man toppled back upon those behind him. Like tenpins they rolled down the stairs. The ancient and rickety structure could not withstand the strain of this unwonted weight and jarring. With a creaking and rending of breaking wood it collapsed beneath the Arabs, leaving Tarzan, Abdul, and the girl alone upon the frail platform at the top.

"Come!" cried the Ouled-Nail. "They will reach us from another stairway through the room next to mine. We have not a moment to spare."

Just as they were entering the room Abdul heard and translated a cry from the yard below for several to hasten to the street and cut off escape from that side.

"We are lost now," said the girl simply.

"We?" questioned Tarzan.

"Yes, m'sieur," she responded; "they will kill me as well. Have I not aided you?"

This put a different aspect on the matter. Tarzan had rather been enjoying the excitement and danger of the encounter. He had not for an instant supposed that either Abdul or the girl could suffer except through accident, and he had only retreated just enough to keep from being killed himself. He had had no intention of running away until he saw that he was hopelessly lost were he to remain.

Alone he could have sprung into the midst of that close-packed mob, and, laying about him after the fashion of Numa, the lion, have struck the Arabs with such consternation that escape would have been easy. Now he must think entirely of these two faithful friends.

He crossed to the window which overlooked the street. In a minute there would be enemies below. Already he could hear the mob clambering the stairway to the next quarters — they would be at the door beside him in another instant. He put a foot upon the sill and leaned out, but he did not look down. Above him, within arm's reach, was the low roof of the building. He called to the girl. She came and stood beside him. He put a great arm about her and lifted her across his shoulder.

"Wait here until I reach down for you from above," he said to Abdul. "In the meantime shove everything in the room against that door — it may delay them long enough." Then he stepped to the sill of the narrow window with the girl upon his shoulders. "Hold tight," he cautioned her. A moment later he had clambered to the roof above with the ease and dexterity of an ape. Setting the girl down, he leaned far over the roof's edge, calling softly to Abdul. The youth ran to the window.

"Your hand," whispered Tarzan. The men in the room beyond were battering at the door. With a sudden crash it fell splintering in, and at the same instant Abdul felt himself lifted like a feather onto the roof above. They were not a moment too soon, for as the men broke into the room which they had just quitted a dozen more rounded the corner in the street below and came running to a spot beneath the girl's window.