In setting the watch for the night one of the sentinels was stationed on the shore about a hundred yards north of the douar. His instructions were to walk a round of about two hundred paces, extending inward from the beach.

Another was placed about the same distance south of the camp, and was to pace backwards and forwards after a similar fashion.

Sailor Bill was stationed on the land side of the camp, where he was to move to and fro between the beats of the two Arab guards, each of whom, on discovering him at the termination of his round, was to utter the word "Akka," so that the sailor should distinguish them from an enemy.

The Arabs themselves were supposed to be sufficiently intelligent to tell a friend from a foe without requiring any countersign.

Before Bill was sent upon his beat, the old sheik went into a tent, and soon after reappeared with a large pistol, bearing a strong likeness to a blunderbuss. This weapon he placed in the sailor's hand, with the injunction—translated to him by the interpreter—not to discharge it until he should be certain of killing either Golah or one of his companions.

The old sailor, although sorely fatigued with the toil of the day's journey, had so great a horror of again becoming the property of the black sheik, that he cheerfully promised to "walk the deck all night, and keep a good lookout for breakers," and his young companions sought repose in full confidence that the promise would be faithfully kept.

Any one of the boy slaves would willingly have taken his place, and allowed their old comrade to rest for the night; but Bill had been selected by the old sheik, and from his decree there was no appeal.

The two Arabs doing duty as sentinels knew, from past experience, that if the Kafila was still followed by Golah, they would be the individuals most exposed to danger; and this knowledge was sufficient to stimulate them to the most faithful discharge of their trust.

Neither of them wished to become victims to the fate which had befallen their predecessors in office.

For two or three hours both paced slowly to and fro; and Bill, each time he approached the end of his beat, could hear distinctly pronounced the word "Akka" which proved that his co-sentinels were fully on the alert.

It so chanced that one of them had no faith in the general belief that the enemy had relinquished his purposes sanguinary of vengeance.

He drew his deductions from Golah's conduct in the past, and during the long silent hours of the night his fancy was constantly dwelling on the manner in which the dreaded enemy had approached the douar on former occasions.

This sentry was the one stationed to the south of the douar; and with eyes constantly striving to pierce the darkness that shrouded the sand plain, the water, on which a better light was reflected, received no attention from him. He believed the douar well protected on the side of the sea, for he had no idea that danger could come from that direction.

He was mistaken.

Had their enemies been, like himself and his companions, true children of the SaÄra, his plan of watching for their approach might have answered well enough; but the latter chanced to be the offspring of a different country and race.

About three hours after the watch had been established, the sentinel placed on the southern side of the douar was being closely observed by the black sheik, yet knew it not.

Golah had chosen a singular plan to secure himself against being observed, similar to that selected by the three mids for the like purpose soon after their being cast away upon the coast.

He had stolen into the water, and with only his woolly occiput above the surface, had approached within a few yards of the spot where the Arab sentry turned upon his round.

In the darkness of the night, at the distance of twelve or fifteen paces, he might have been discovered, had a close survey been made of the shining surface. But there was no such survey, and Golah watched the sentinel, himself unseen.

The attention of the Arab was wholly occupied in looking for the approach of a foe from the land side; and while he was in continual fear of hearing the report of a musket, or feeling the stroke of its bullet.

This disagreeable surprise he never expected could come from the sea, but was so fully anticipated from the land, that he paid but little or no attention to the restless waves that were breaking with low moans against the beach.

As he turned his back upon the water for the hundredth time, with the intention of walking to the other end of his beat, Golah crept gently out of the water and hastened after him.

The deep sighing of the waves against the shingly shore hindered the sound of footsteps from being heard.

Golah was only armed with a scimitar; but it was a weapon that, in his hands, was sure to fall with deadly effect. It was a weapon of great size and weight, having been made expressly for himself; and with this upraised, he silently but swiftly glided after the unconscious Arab.

Adding the whole strength of his powerful arm to the weight of the weapon, the black sheik brought its sharp edge slantingly down upon the neck of the unsuspecting sentinel.

With a low moan, that sounded in perfect harmony with the sighing of the waves, the Arab fell to the earth, leaving his musket in the huge hand his assassin had stretched forth to grasp it. Putting the gun to full cock, Golah walked on in the direction in which the sentry had been going. He intended next to encounter the man who was guarding the eastern side of the douar. Walking boldly on, he took no trouble to avoid the sound of his footsteps being heard, believing that he would be taken for the sentry he had just slain. After going about a hundred paces without seeing any one, he paused, and with his large fiercely gleaming eyes strove to penetrate the surrounding gloom. Still no one was to be seen, and he laid himself along the earth to listen for footfalls.

Nothing could be heard; but after glancing for some moments along the ground, he saw a dark object outlined above the surface. Unable, from the distance, to form a correct idea of what it was, he cautiously advanced towards it, keeping on all fours, till he could see that the object was a human being, prostrate on the ground, and apparently listening, like himself. Why should the man be listening? Not to note the approach of his companion, for that should be expected without suspicion, as his attitude would indicate. He might be asleep, reasoned Golah. If so, Fortune seemed to favor him, and with this reflection he steadily moved on towards the prostrate form.

Though the latter moved not, still Golah was not quite sure that the sentry was asleep. Again he paused, and for a moment fixed his eyes on the body with a piercing gaze. If the man was not sleeping, why should he allow an enemy to approach so near? Why lie so quietly, without showing any sign or giving an alarm? If Golah could despatch this sentinel as he had done the other, without making any noise, he would, along with his two relatives (who were waiting the result of his adventure), afterwards steal into the douar, and all he had lost might be again recovered.

The chance was worth the risk, so thought Golah, and silently moved on.

As he drew nearer, he saw that the man was lying on his side, with his face turned towards him, and partly concealed by one arm.

The black sheik could see no gun in his hands, and consequently there would be but little danger in an encounter with him, if such should chance to arise.

Golah grasped the heavy scimitar in his right hand, evidently intending to despatch his victim as he had done the other, with a single blow.

The head could be severed from the body at one stroke, and no alarm would be given to the slumbering camp.

The heavy blade of shining steel was raised aloft; and the gripe of the powerful hand clutching its hilt became more firm and determined.

Sailor Bill! has your promise to keep a sharp lookout been broken so soon?

Beware! Golah is near with strength in his arm, and murder in his mind!