"Not asleep, Dorrell?"

Tom grunted, but did not stir. Another minute or two, then he suddenly jumped up.

"Well, I think I've got it," he said, and he chuckled.

"What is it?"

"Come along. I'll explain as we go."

The two mounted the car; Tom started the ascensional screws; and the airship rose slowly from the hill. When they had left the ground some three hundred feet beneath them they saw, a mile or more distant, the body of hors.e.m.e.n who had set off in pursuit from the Moors' encampment.

The airship was headed in the direction from which they had come, and when they saw it they halted, and waited until it had soared past them; then, having no doubt that it was returning to the hill with the intention of again attempting to rescue the blockaded men, they wheeled round, and galloped in pursuit.

The airship was going at only a moderate speed, so that the hors.e.m.e.n were able to keep pace with it. Tom chuckled again, and Oliphant, to whom he had by this time imparted his notion, seemed to find great amus.e.m.e.nt in the sight.

"The beggars little imagine they're playing our game," he said.

"No, indeed. I wonder what they really are thinking. Probably they fancy something has gone wrong with our works and we can't go any faster."

"D'you think they've got wind of our former breakdown?"

"It's not unlikely. News travels very fast in these countries that haven't got the telegraph!"

When they arrived at the hill of the caves, there appeared to be no change in the situation. A small group of four or five men were squatting on the summit; more than a score were congregated below. All eyes were directed upwards as the airship again came into view, and the men laughed, recognizing how fruitless would be any renewed attempt to rescue the prisoners. They all carried rifles, and evidently intended to use them when the vessel came within range. But it pa.s.sed too high above their heads, still going very slowly, and, so far from descending towards the cave, sailed on towards the sea. It crossed one of the adjacent hills, then sank a little, so that it was only visible then to the few men who kept watch above.

But a minute or two afterwards the occupants of the car, looking round, saw that these men were on their feet, gesticulating with great excitement.

"They've taken the bait!" cried Oliphant, laughing outright.

The men had noticed that the airship, instead of continuing its north-westerly course, had suddenly taken a turn to the left, and was making at tremendous speed straight for the village of Ain Afroo. Rising higher into the air, so that he could get a view over the shoulder of the hill, Tom saw that the whole body of hors.e.m.e.n, now joined by the sheikh and his party, were riding at a mad gallop for the village. By this time the airship was a mile ahead of them, and the two Englishmen laughed heartily as they watched the frantic efforts of the Moors to reduce the gap. They were left hopelessly behind, and were still more than a mile from the walls when the airship, hovering directly over the roof of the kasbah, began very slowly to drop earthwards as if a descent were going to be made on the spot where it had formerly rested.

The descent took a considerable time. Who was there to tell the frenzied hors.e.m.e.n that the accursed Firangi was playing with them? They urged their foaming steeds up the hill at a furious rate, making light of all obstacles, and extorting a tribute of admiration from the Englishmen for horses and riders alike. They clattered into the village, dashed through the street, pulled the horses up on their haunches at the door of the kasbah, flung themselves from the saddles, and poured into the patio and up the stairs.

The sheikh himself, by far the best mounted of the troop, was the first to arrive; and within a few seconds he sprang out of the opening on the roof, followed closely by several members of his household. But what was this? The airship, instead of resting on the flagged roof, was hundreds of feet above them, and, horror of horrors! sailing with terrific speed back towards the hill of the caves. For a few moments the Moors stood gazing in bewilderment, being joined by more men from below. Then, with hearty Moslem curses, they rushed back to the opening, toppling over one another, stumbling down the stairs in their haste. Down into the patio, out of the gate, on to their horses' backs once more, and off they set, pell-mell after the airship.

But the horses were badly blown. There were four miles of heavy country to cover. And by the time they were again clear of the walls the airship was halfway to the hill.

Tom and his friend were hugely delighted with the success of their simple bit of strategy. They could see the hors.e.m.e.n like ants in the distance beneath, urging their poor panting horses to the utmost of their capacity.

"We ought to have plenty of time to get them away," said Tom.

"Yes, but hang it all! we've clean forgotten that we can't lift both Schwab and the Moor."

"Great Scott!" Tom e.j.a.c.u.l.a.t.ed, in consternation. But in a moment his face cleared. "We'll manage that," he said cheerfully. But then he received another shock. He saw that the four or five men who had held their watch on the plateau were still there: they had not followed the rest. Their horses could be seen tethered in the grove beneath, and the men were gathered in a knot, watching the rapid approach of the machine, which probably they had expected to see no more.

"There's only one thing for it," said Tom. "We must go slap at them, and trust to luck. If they shoot, they may do so before we are within range, and at this speed they may easily miss us. They are sure to be a bit nervous, too."

Tom had already begun the descent, obliquely upon the hill. When the airship was, as nearly as he could calculate, on a level with the summit, he again put the engines to their utmost speed, and dashed straight at the little group. There were three or four reports almost simultaneously, and above the whirr of the screws Tom thought he heard a sound of rending, as if one of the planes had been struck by a bullet.

The vessel, indeed, dipped slightly, and for a moment he feared that it would be dashed against the face of the hill. But he jerked up the lever controlling the planes, the airship rose the few feet necessary to clear the summit, and once more sped on its course.

By this time, however, the group on the hilltop had taken fright. They could not know that if the airship dashed into them, they would be as formidable to it as it could be to them. Even if they had known this, they would probably not have been willing to sell their lives, even though in doing so they should break up the machine and hurl its occupants to destruction. With one consent they broke and fled.

Tom instantly reversed the engines, and the airship glided slowly to rest on the plateau. But the path by which the fugitives were attempting to make good their flight was only wide enough to accommodate one man at a time, and that with difficulty. Only three of the men had begun to descend when Tom sprang out of the car. The other two, fearing to be attacked from behind, turned instinctively to meet the supposed danger.

Then, seeing that they had only two men to deal with, and feeling no doubt that they would be completely at the mercy of these men when once they had begun the descent, they hesitated for a second at the brink.

If they had used this second to draw their formidable knives, Tom's adventure might have ended there and then, for in his eagerness he had forgotten to s.n.a.t.c.h up his revolver. But their halt was due rather to nervousness than to courage, and Tom was never lacking in prompt.i.tude at the critical moment. He dashed straight at them. One of them swung round at once and slithered down the path. The other, somewhat more mettlesome, made a grab at his knife. But he had only half drawn it from his belt when Tom's fist shot out and tumbled him headlong after his comrade. The result would have been amusing if Tom had had time to observe it. From top to bottom of that rocky declivity there was an avalanche of Moors. The impetus with which the topmost man had been shot over the edge sent him smack into the man next below. The two then rolled, or rather pitched, on top of those who had preceded them, and were making their way quickly yet laboriously down the steep tracks, and it is to be feared that there were bruised and broken limbs at the bottom.

But Tom had neither eyes nor ears for the discomfiture of his enemies.

There was still much to be done before he could be sure that his friends and his airship were out of harm's way. One of his friends was already taking things into his own hands. At the first hint of what was happening Abdul had left the mouth of the cave, and was now swarming up the perilous face of the hillside. Breathless he came over the brink, on the opposite side from that where the Moors had disappeared, almost before Tom could turn round.

"All well below?" asked Tom.

"Yes, master."

"Can you bring up the big man?"

"With a rope, master."

"Quick, then: we have no time to spare."

"And the Hudi, master?"

"What of him?"

"He made them come. We tied him, feet and hands."

"Untie him, but leave him. He can make them come again!"

A rope was quickly unshipped from the car and strongly looped. Abdul descended, the rope being held by both Oliphant and Tom above, who, doubtful whether their strength would stand the strain of the ponderous German's weight, hitched it round a rocky prominence at the brink of the hill. But fear lent Schwab extraordinary agility-as once before in the enclosure of Midfont House. With the rope looped about him, he hauled himself up by it, a.s.sisting his progress with his feet against the hill.

He was in a bath of perspiration, his fat face was pale as death, when he reached the top and sank exhausted at Tom's feet. Oliphant and Tom together hoisted him into the car, and by the time he was settled, Abdul had cut the Jew's bonds and again clambered up, pursued by entreaties, wild threats, execrations, from the luckless Salathiel ben Ezra.

Glancing in the direction of Ain Afroo, Tom rejoiced to see that he had still about ten minutes to spare before the pursuing hors.e.m.e.n could arrive at the spot. He knew from experience that with Schwab as a pa.s.senger the ascensional screws did not exert sufficient power to lift three other men; but when Oliphant had reminded him of this, a way out of the difficulty suggested itself. If once the airship could be raised from the ground and the horizontal screws set in motion, it was likely that, with the speed thus obtained, they might suffice (the planes being inclined at the proper angle) to overcome the downward pull of gravity.

Tom rapidly explained to Abdul the plan he had formed. Then, entering the car in which Schwab and Oliphant already were, he set the ascensional screws in motion. The vessel slowly rose. Meanwhile Abdul had looped about his body the rope by which Schwab had been hauled up, the upper end of which had again been securely attached to the car. When the airship had risen a few feet from the hill-top, Tom set the horizontal engines at full speed, and the vessel sailed beyond the plateau, Abdul dangling from it at the end of the rope, as he had done once before when rescued from the shark. He showed no fear; in the loop he was perfectly safe, for even if the vessel sank with his weight, it would be so slowly that he would run no risk of being brought too violently into contact with the ground.

As Tom had expected, the vessel did not sink. But, the horizontal screws being partly engaged in counteracting the force of gravity, the speed of the airship was reduced to only five or six miles an hour, and at that rate it was evident that the fuel would not hold out until they reached the coast. A second breakdown must be averted at all costs; it was unlikely that they would be able to escape the clutches of predatory Moors a second time. No doubt the story of what had happened before had spread for many miles through the country, and short shrift would be given to the aeronauts if again they were brought to earth.

There was now only a minute or two to spare before the sheikh would arrive. Whatever could be done must be done at once. Glancing down, Tom saw below him the horses belonging to the men who had just been tumbled from the plateau. The men themselves were lying at the foot of the hill, not dead, as Tom was glad to see-the rugged declivity had broken their fall-but evidently completely disabled. Without hesitation Tom reduced the speed of the engines and descended, shouting to Abdul, who at the end of the rope would of course reach the ground first, to secure two of the best horses, and follow as fast as he could in the track of the airship.

Owing to the delay that had occurred, Abdul had only just leapt into the saddle when the hors.e.m.e.n came into sight scarcely half a mile away. The sheikh was far ahead of his men, and the pace even of his splendid Arab showed that there was little fear of Abdul being overtaken. The young Moor set off at a gallop, a second horse at his side. There was a shout behind him; the sheikh called upon his followers to spur their flagging steeds: clearly he intended gamely to continue the pursuit.

But the fugitives were now well away. Tom accommodated the speed of the airship to the pace of the horses below, keeping at a height of no more than a hundred feet from the ground so as to be able to drop down and stand by Abdul in case of need. For a few minutes it seemed as though the lad was to be close pressed, in spite of the hard galloping the horses of the pursuers had already done. But gradually they dropped farther and farther behind; Abdul's horses were fresh; he himself was a light weight; and Tom began to breathe more freely.

Another danger, however, occurred to him. The country was at present wild and desolate, with no signs of habitation. But as he neared the coast, he would undoubtedly pa.s.s scattered villages and towns, and it was possible that Abdul might be checked at one of these. He therefore felt it desirable to rise to a greater height, so that he might obtain a more extensive outlook over the country and indicate to Abdul a course which would prevent him from running into danger.

He soon saw that his precaution was justified. The pursuers were still sticking doggedly to the trail, and Tom noticed that from time to time they were joined by fresh hors.e.m.e.n from the hamlets through which they pa.s.sed. He could not distinguish figures in the distance, but he had no doubt that the sheikh had already obtained a fresh horse, and was among a group which had far outstripped the rest of the troop and was gradually diminishing the distance between them and their quarry. Abdul was riding gallantly on, changing from horse to horse with admirable dexterity; but it was clear that the pursuers, with many opportunities of obtaining remounts, must in course of time run him down. The airship would always indicate the direction in which they should ride.

Again Tom had to devise a means of overcoming a new difficulty. The chase had now lasted some hours, and the matter was becoming urgent. By good luck, the sight of a high conical hill, well wooded, somewhat to the right of the course they had been following, suggested a plan.

Lowering the airship to within easy speaking distance of the Moor-a manuvre which caused some uneasiness to his horses, tired as they were-Tom directed him to make for this hill, and remain in hiding among the trees until rejoined. At the moment he thought of making all speed to the yacht, dropping Schwab, replenishing his can of fuel, and returning for Abdul. But a little consideration caused him to change his mind. It might prove a very difficult matter to find the hill again when returning. It must be, he guessed, at least sixty miles from the sea, and he could not remember the landmarks exactly enough to be able to retrace his course.