On the same day that Kadour ben Saden rode south the diligence from the north brought Tarzan a letter from D'Arnot which had been forwarded from Sidi-bel-Abbes. It opened the old wound that Tarzan would have been glad to have forgotten; yet he was not sorry that D'Arnot had written, for one at least of his subjects could never cease to interest the ape-man. Here is the letter:

MY DEAR JEAN:

Since last I wrote you I have been across to London on a matter of
business.  I was there but three days.  The very first day I came
upon an old friend of yours--quite unexpectedly--in Henrietta
Street.  Now you never in the world would guess whom.  None other
than Mr. Samuel T. Philander.  But it is true.  I can see your
look of incredulity.  Nor is this all.  He insisted that I return
to the hotel with him, and there I found the others--Professor
Archimedes Q. Porter, Miss Porter, and that enormous black woman,
Miss Porter's maid--Esmeralda, you will recall.  While I was there
Clayton came in.  They are to be married soon, or rather sooner,
for I rather suspect that we shall receive announcements almost
any day.  On account of his father's death it is to be a very quiet
affair--only blood relatives.

While I was alone with Mr. Philander the old fellow became rather
confidential.  Said Miss Porter had already postponed the wedding
on three different occasions.  He confided that it appeared to him
that she was not particularly anxious to marry Clayton at all; but
this time it seems that it is quite likely to go through.

Of course they all asked after you, but I respected your wishes
in the matter of your true origin, and only spoke to them of your
present affairs.

Miss Porter was especially interested in everything I had to say
about you, and asked many questions.  I am afraid I took a rather
unchivalrous delight in picturing your desire and resolve to go back
eventually to your native jungle.  I was sorry afterward, for it
did seem to cause her real anguish to contemplate the awful dangers
to which you wished to return.  "And yet," she said, "I do not
know.  There are more unhappy fates than the grim and terrible
jungle presents to Monsieur Tarzan.  At least his conscience will
be free from remorse.  And there are moments of quiet and restfulness
by day, and vistas of exquisite beauty.  You may find it strange
that I should say it, who experienced such terrifying experiences
in that frightful forest, yet at times I long to return, for I cannot
but feel that the happiest moments of my life were spent there."

There was an expression of ineffable sadness on her face as
she spoke, and I could not but feel that she knew that I knew her
secret, and that this was her way of transmitting to you a last
tender message from a heart that might still enshrine your memory,
though its possessor belonged to another.

Clayton appeared nervous and ill at ease while you were the subject
of conversation.  He wore a worried and harassed expression.  Yet
he was very kindly in his expressions of interest in you.  I wonder
if he suspects the truth about you?

Tennington came in with Clayton.  They are great friends, you know.
He is about to set out upon one of his interminable cruises in that
yacht of his, and was urging the entire party to accompany him.
Tried to inveigle me into it, too.  Is thinking of circumnavigating
Africa this time.  I told him that his precious toy would take him
and some of his friends to the bottom of the ocean one of these
days if he didn't get it out of his head that she was a liner or
a battleship.

I returned to Paris day before yesterday, and yesterday I met the
Count and Countess de Coude at the races.  They inquired after
you.  De Coude really seems quite fond of you.  Doesn't appear to
harbor the least ill will.  Olga is as beautiful as ever, but a
trifle subdued.  I imagine that she learned a lesson through her
acquaintance with you that will serve her in good stead during the
balance of her life.  It is fortunate for her, and for De Coude as
well, that it was you and not another man more sophisticated.

Had you really paid court to Olga's heart I am afraid that there
would have been no hope for either of you.

She asked me to tell you that Nikolas had left France.  She paid him
twenty thousand francs to go away, and stay.  She is congratulating
herself that she got rid of him before he tried to carry out a
threat he recently made her that he should kill you at the first
opportunity.  She said that she should hate to think that her
brother's blood was on your hands, for she is very fond of you,
and made no bones in saying so before the count.  It never for a
moment seemed to occur to her that there might be any possibility
of any other outcome of a meeting between you and Nikolas.  The
count quite agreed with her in that.  He added that it would take
a regiment of Rokoffs to kill you.  He has a most healthy respect
for your prowess.

Have been ordered back to my ship.  She sails from Havre in
two days under sealed orders.  If you will address me in her
care, the letters will find me eventually.  I shall write you
as soon as another opportunity presents.
                                    Your sincere friend,
                                                PAUL D'ARNOT.

"I fear," mused Tarzan, half aloud, "that Olga has thrown away her twenty thousand francs."

He read over that part of D'Arnot's letter several times in which he had quoted from his conversation with Jane Porter. Tarzan derived a rather pathetic happiness from it, but it was better than no happiness at all.

The following three weeks were quite uneventful. On several occasions Tarzan saw the mysterious Arab, and once again he had been exchanging words with Lieutenant Gernois; but no amount of espionage or shadowing by Tarzan revealed the Arab's lodgings, the location of which Tarzan was anxious to ascertain.

Gernois, never cordial, had kept more than ever aloof from Tarzan since the episode in the dining-room of the hotel at Aumale. His attitude on the few occasions that they had been thrown together had been distinctly hostile.

That he might keep up the appearance of the character he was playing, Tarzan spent considerable time hunting in the vicinity of Bou Saada. He would spend entire days in the foothills, ostensibly searching for gazelle, but on the few occasions that he came close enough to any of the beautiful little animals to harm them he invariably allowed them to escape without so much as taking his rifle from its boot. The ape-man could see no sport in slaughtering the most harmless and defenseless of God's creatures for the mere pleasure of killing.

In fact, Tarzan had never killed for "pleasure," nor to him was there pleasure in killing. It was the joy of righteous battle that he loved--the ecstasy of victory. And the keen and successful hunt for food in which he pitted his skill and craftiness against the skill and craftiness of another; but to come out of a town filled with food to shoot down a soft-eyed, pretty gazelle--ah, that was crueller than the deliberate and cold-blooded murder of a fellow man. Tarzan would have none of it, and so he hunted alone that none might discover the sham that he was practicing.

And once, probably because of the fact that he rode alone, he was like to have lost his life. He was riding slowly through a little ravine when a shot sounded close behind him, and a bullet passed through the cork helmet he wore. Although he turned at once and galloped rapidly to the top of the ravine, there was no sign of any enemy, nor did he see aught of another human being until he reached Bou Saada.

"Yes," he soliloquized, in recalling the occurrence, "Olga has indeed thrown away her twenty thousand francs."

That night he was Captain Gerard's guest at a little dinner.

"Your hunting has not been very fortunate?" questioned the officer.

"No," replied Tarzan; "the game hereabout is timid, nor do I care particularly about hunting game birds or antelope. I think I shall move on farther south, and have a try at some of your Algerian lions."

"Good!" exclaimed the captain. "We are marching toward Djelfa on the morrow. You shall have company that far at least. Lieutenant Gernois and I, with a hundred men, are ordered south to patrol a district in which the marauders are giving considerable trouble. Possibly we may have the pleasure of hunting the lion together--what say you?"

Tarzan was more than pleased, nor did he hesitate to say so; but the captain would have been astonished had he known the real reason of Tarzan's pleasure. Gernois was sitting opposite the ape-man. He did not seem so pleased with his captain's invitation.

"You will find lion hunting more exciting than gazelle shooting," remarked Captain Gerard, "and more dangerous."

"Even gazelle shooting has its dangers," replied Tarzan. "Especially when one goes alone. I found it so today. I also found that while the gazelle is the most timid of animals, it is not the most cowardly."

He let his glance rest only casually upon Gernois after he had spoken, for he did not wish the man to know that he was under suspicion, or surveillance, no matter what he might think. The effect of his remark upon him, however, might tend to prove his connection with, or knowledge of, certain recent happenings. Tarzan saw a dull red creep up from beneath Gernois' collar. He was satisfied, and quickly changed the subject.

When the column rode south from Bou Saada the next morning there were half a dozen Arabs bringing up the rear.

"They are not attached to the command," replied Gerard in response to Tarzan's query. "They merely accompany us on the road for companionship."

Tarzan had learned enough about Arab character since he had been in Algeria to know that this was no real motive, for the Arab is never overfond of the companionship of strangers, and especially of French soldiers. So his suspicions were aroused, and he decided to keep a sharp eye on the little party that trailed behind the column at a distance of about a quarter of a mile. But they did not come close enough even during the halts to enable him to obtain a close scrutiny of them.

He had long been convinced that there were hired assassins on his trail, nor was he in great doubt but that Rokoff was at the bottom of the plot. Whether it was to be revenge for the several occasions in the past that Tarzan had defeated the Russian's purposes and humiliated him, or was in some way connected with his mission in the Gernois affair, he could not determine. If the latter, and it seemed probable since the evidence he had had that Gernois suspected him, then he had two rather powerful enemies to contend with, for there would be many opportunities in the wilds of Algeria, for which they were bound, to dispatch a suspected enemy quietly and without attracting suspicion.

After camping at Djelfa for two days the column moved to the southwest, from whence word had come that the marauders were operating against the tribes whose DOUARS were situated at the foot of the mountains.

The little band of Arabs who had accompanied them from Bou Saada had disappeared suddenly the very night that orders had been given to prepare for the morrow's march from Djelfa. Tarzan made casual inquiries among the men, but none could tell him why they had left, or in what direction they had gone. He did not like the looks of it, especially in view of the fact that he had seen Gernois in conversation with one of them some half hour after Captain Gerard had issued his instructions relative to the new move. Only Gernois and Tarzan knew the direction of the proposed march. All the soldiers knew was that they were to be prepared to break camp early the next morning. Tarzan wondered if Gernois could have revealed their destination to the Arabs.

Late that afternoon they went into camp at a little oasis in which was the DOUAR of a sheik whose flocks were being stolen, and whose herdsmen were being killed. The Arabs came out of their goatskin tents, and surrounded the soldiers, asking many questions in the native tongue, for the soldiers were themselves natives. Tarzan, who, by this time, with the assistance of Abdul, had picked up quite a smattering of Arab, questioned one of the younger men who had accompanied the sheik while the latter paid his respects to Captain Gerard.

No, he had seen no party of six horsemen riding from the direction of Djelfa. There were other oases scattered about--possibly they had been journeying to one of these. Then there were the marauders in the mountains above--they often rode north to Bou Saada in small parties, and even as far as Aumale and Bouira. It might indeed have been a few marauders returning to the band from a pleasure trip to one of these cities.

Early the next morning Captain Gerard split his command in two, giving Lieutenant Gernois command of one party, while he headed the other. They were to scour the mountains upon opposite sides of the plain.

"And with which detachment will Monsieur Tarzan ride?" asked the captain. "Or maybe it is that monsieur does not care to hunt marauders?"

"Oh, I shall be delighted to go," Tarzan hastened to explain. He was wondering what excuse he could make to accompany Gernois. His embarrassment was short-lived, and was relieved from a most unexpected source. It was Gernois himself who spoke.

"If my captain will forego the pleasure of Monsieur Tarzan's company for this once, I shall esteem it an honor indeed to have monsieur ride with me today," he said, nor was his tone lacking in cordiality. In fact, Tarzan imagined that he had overdone it a trifle, but, even so, he was both astounded and pleased, hastening to express his delight at the arrangement.

And so it was that Lieutenant Gernois and Tarzan rode off side by side at the head of the little detachment of SPAHIS. Gernois' cordiality was short-lived. No sooner had they ridden out of sight of Captain Gerard and his men than he lapsed once more into his accustomed taciturnity. As they advanced the ground became rougher. Steadily it ascended toward the mountains, into which they filed through a narrow canon close to noon. By the side of a little rivulet Gernois called the midday halt. Here the men prepared and ate their frugal meal, and refilled their canteens.

After an hour's rest they advanced again along the canon, until they presently came to a little valley, from which several rocky gorges diverged. Here they halted, while Gernois minutely examined the surrounding heights from the center of the depression.

"We shall separate here," he said, "several riding into each of these gorges," and then he commenced to detail his various squads and issue instructions to the non-commissioned officers who were to command them. When he had done he turned to Tarzan. "Monsieur will be so good as to remain here until we return."

Tarzan demurred, but the officer cut him short. "There may be fighting for one of these sections," he said, "and troops cannot be embarrassed by civilian noncombatants during action."

"But, my dear lieutenant," expostulated Tarzan, "I am most ready and willing to place myself under command of yourself or any of your sergeants or corporals, and to fight in the ranks as they direct. It is what I came for."

"I should be glad to think so," retorted Gernois, with a sneer he made no attempt to disguise. Then shortly: "You are under my orders, and they are that you remain here until we return. Let that end the matter," and he turned and spurred away at the head of his men. A moment later Tarzan found himself alone in the midst of a desolate mountain fastness.

The sun was hot, so he sought the shelter of a nearby tree, where he tethered his horse, and sat down upon the ground to smoke. Inwardly he swore at Gernois for the trick he had played upon him. A mean little revenge, thought Tarzan, and then suddenly it occurred to him that the man would not be such a fool as to antagonize him through a trivial annoyance of so petty a description. There must be something deeper than this behind it. With the thought he arose and removed his rifle from its boot. He looked to its loads and saw that the magazine was full. Then he inspected his revolver. After this preliminary precaution he scanned the surrounding heights and the mouths of the several gorges--he was determined that he should not be caught napping.

The sun sank lower and lower, yet there was no sign of returning SPAHIS. At last the valley was submerged in shadow Tarzan was too proud to go back to camp until he had given the detachment ample time to return to the valley, which he thought was to have been their rendezvous. With the closing in of night he felt safer from attack, for he was at home in the dark. He knew that none might approach him so cautiously as to elude those alert and sensitive ears of his; then there were his eyes, too, for he could see well at night; and his nose, if they came toward him from up-wind, would apprise him of the approach of an enemy while they were still a great way off.

So he felt that he was in little danger, and thus lulled to a sense of security he fell asleep, with his back against the tree.

He must have slept for several hours, for when he was suddenly awakened by the frightened snorting and plunging of his horse the moon was shining full upon the little valley, and there, not ten paces before him, stood the grim cause of the terror of his mount.

Superb, majestic, his graceful tail extended and quivering, and his two eyes of fire riveted full upon his prey, stood Numa EL ADREA, the black lion. A little thrill of joy tingled through Tarzan's nerves. It was like meeting an old friend after years of separation. For a moment he sat rigid to enjoy the magnificent spectacle of this lord of the wilderness.

But now Numa was crouching for the spring. Very slowly Tarzan raised his gun to his shoulder. He had never killed a large animal with a gun in all his life--heretofore he had depended upon his spear, his poisoned arrows, his rope, his knife, or his bare hands. Instinctively he wished that he had his arrows and his knife--he would have felt surer with them.

Numa was lying quite flat upon the ground now, presenting only his head. Tarzan would have preferred to fire a little from one side, for he knew what terrific damage the lion could do if he lived two minutes, or even a minute after he was hit. The horse stood trembling in terror at Tarzan's back. The ape-man took a cautious step to one side--Numa but followed him with his eyes. Another step he took, and then another. Numa had not moved. Now he could aim at a point between the eye and the ear.

His finger tightened upon the trigger, and as he fired Numa sprang. At the same instant the terrified horse made a last frantic effort to escape--the tether parted, and he went careening down the canon toward the desert.

No ordinary man could have escaped those frightful claws when Numa sprang from so short a distance, but Tarzan was no ordinary man. From earliest childhood his muscles had been trained by the fierce exigencies of his existence to act with the rapidity of thought. As quick as was EL ADREA, Tarzan of the Apes was quicker, and so the great beast crashed against a tree where he had expected to feel the soft flesh of man, while Tarzan, a couple of paces to the right, pumped another bullet into him that brought him clawing and roaring to his side.

Twice more Tarzan fired in quick succession, and then EL ADREA lay still and roared no more. It was no longer Monsieur Jean Tarzan; it was Tarzan of the Apes that put a savage foot upon the body of his savage kill, and, raising his face to the full moon, lifted his mighty voice in the weird and terrible challenge of his kind--a bull ape had made his kill. And the wild things in the wild mountains stopped in their hunting, and trembled at this new and awful voice, while down in the desert the children of the wilderness came out of their goatskin tents and looked toward the mountains, wondering what new and savage scourge had come to devastate their flocks.

A half mile from the valley in which Tarzan stood, a score of white-robed figures, bearing long, wicked-looking guns, halted at the sound, and looked at one another with questioning eyes. But presently, as it was not repeated, they took up their silent, stealthy way toward the valley.

Tarzan was now confident that Gernois had no intention of returning for him, but he could not fathom the object that had prompted the officer to desert him, yet leave him free to return to camp. His horse gone, he decided that it would be foolish to remain longer in the mountains, so he set out toward the desert.

He had scarcely entered the confines of the canon when the first of the white-robed figures emerged into the valley upon the opposite side. For a moment they scanned the little depression from behind sheltering bowlders, but when they had satisfied themselves that it was empty they advanced across it. Beneath the tree at one side they came upon the body of EL ADREA. With muttered exclamations they crowded about it. Then, a moment later, they hurried down the canon which Tarzan was threading a brief distance in advance of them. They moved cautiously and in silence, taking advantage of shelter, as men do who are stalking man.