He imparted his conclusion to Rejeb.
"Wallahi!" exclaimed the chief. "An evil spirit is striving against us."
One thought had flashed upon the young men at the same moment. They might rout the Turks, but lose the aeroplane. The enemy would no doubt place on the deck of the launch not only the machine, but their prisoner, and the Arabs could not fire on the crew without the risk of hitting the Englishman. It was possible, of course, to hold up the launch and prevent it from passing up the wady, but the sound of rifle shots could not fail to be heard by the Turks conveying the aeroplane, and the alarm would ruin the chances of a successful ambuscade.
While Rejeb and Burnet were discussing the matter in low tones, they peered out through the reeds in the direction of the rapidly approaching sounds. Soon they caught sight of six horsemen riding in couples along the bank of the wady, and as they drew abreast, the launch became visible beneath their horses' bellies. One of the horsemen was an officer, whom no doubt the news brought him at the outpost had induced to ride back with the messengers and see for himself the captured aeroplane.
Launch and horsemen passed out of sight. During the few moments' pause in the conversation while the enemy went by, an idea had occurred to Burnet. It was probable that the aeroplane had barely arrived at the bank of the wady, and, judging by the direction of its captors' march, at a point at least five or six miles from the ruins. The launch was keeping pace with the horsemen on the bank; it might reach the aeroplane in something under an hour. Further time would be occupied in explanation; no doubt the officer from the outpost would be curious enough to examine the machine; then its safe bestowal on the deck of the launch would be a long job. Probably two or three hours would elapse before the return journey commenced, and Burnet had conceived a plan for utilising those hours.
He mentioned it to Rejeb, who received it with a torrent of joyous ejaculations. There was no time to be lost. The chief told off a man to go on foot half a mile along the bank of the wady, to give warning of the enemy's approach. The course of the channel was almost perfectly straight, and horsemen riding along the embankment could be seen from a great distance. Then he selected twenty men, and placed them at Burnet's orders. Burnet took them down to the brink of the wady, chose a spot favourable to his design about half-way through the ruins, and instructed the men to build a dam with the material that lay close to their hands. The channel was shallow, and only about forty feet wide. The men formed two queues, and masses of brick and stone were passed from hand to hand and dumped in the middle.
Working with interest and hearty good-will, within an hour the Arabs had raised that obstacle almost to the surface, and in the muddy water it was scarcely visible, even from the bank. Much less was it likely to be seen from the deck of the moving launch, the crew of which would not suspect that the channel they had already navigated safely could hold any danger for them.
Having completed the dam, the men returned to their former posts. No change in the general plan was necessitated: indeed, the sudden stoppage of the launch would tend to further it, for it would add one more element to the confusion.
It was now only a question of waiting. The Arabs sat their horses in stolid patience, scarcely moving or speaking. Burnet was more restless. He would have liked to steal along the bank of the wady, and watch the stages in the enemy's progress; but he contained himself, and tried to emulate the stillness of his friend the chief.
Three hours passed: it was almost midday when the Arab scout came running back with the news that the enemy were in sight. Soon afterwards the sound of the propeller was heard, and then, peeping through the reeds, the watchers saw the horsemen riding two by two at a walking pace along the embankment, and the aeroplane, its wings extending over the banks on either side, as it were floating on the stream.