"Hark!" he whispered excitedly. "Listen! Do you not hear?"

Frank shook his head.

"It is quite plain," continued the Sheikh. "Horses--the trampling of many men. Keep close together, Excellencies, while I warn my people."

"Warn them of what?" said the doctor calmly.

"Danger, Excellency. These may be friends coming, but it may mean an attack or the coming of strangers. If it is either of the latter I shall try to lead you all into safety. So at a word follow me at once straight away into the desert. We may be able to escape."

The Sheikh's camel glided silently away into the darkness, and the party sat straining their sense of hearing to the utmost, making out plainly enough now the dull sound of trampling hoofs, the jingling of trappings, and every now and then an angry snort or squeal as some ill-tempered beast resented the too near approach of one of its own kind.

Then all at once, as the sounds came nearer, there was heard plainly enough the muttering, whining cry of a camel, followed by more and more proofs then that the coming party was one of greater strength than it had seemed to be at first.

Just then the Sheikh came back out of the darkness, to halt his camel close up by the professor's.

"It is not English cavalry, Excellencies," he said, "but a native force.

I think it must be the Baggara chief and his men returned."

At that moment a peculiar cry rang out from a couple of hundred yards or so away--a weird, strange whoop that might have come from some night bird sweeping through the darkness overhead.

But it was human, and answered directly by the Baggara train close at hand, and directly after there was a loud shout, and a crowd of hors.e.m.e.n galloped up out of the mysterious-looking gloom, to mingle with the party about to start on their desert ride.

CHAPTER TWENTY TWO.

NEARING THE GOAL.

It was more from hearing than seeing that Frank Frere gathered the fact that the Baggara chief had returned, for after a short pause the camel train was once more in motion, and they were ordered to keep steadily in line in the advance to the desert in the opposite direction to that by which the newcomers had arrived.

At first the two parties formed the train alone, for the fresh arrivals had halted to water their horses and camels, quite an hour pa.s.sing before the sound of approaching hors.e.m.e.n announced that the whole force was in motion, overtaking them at a sharp canter, but only to subside directly into the regular, slow camel pace, which was kept on hour after hour till the dawn, when, looking back, Frank made out that the train extended for nearly half a mile to the rear, being made up of a long line of camels, followed by a troop of many hors.e.m.e.n.

It was nearly all surmise, but judging from the number of camels, which were certainly double those that the Baggara had before during their stay by the fountains, they had been engaged in some successful foray, for as the light grew stronger the baggage animals seemed to be very heavily laden.

This idea naturally suggested that the wild hors.e.m.e.n had been engaged in some desperate encounter, and half laughingly the professor bantered his friends about their prospects.

"It means a revival of professional practice for you," he said, "and that looks prosperous. You only lost your last patient a few hours ago--that is, if you have lost him--and now a score or two will come tumbling in."

"Very well," said the doctor coolly; "it shows that they approve of my treatment. I suppose we shall know at the first halt."

This was many hours in coming, for a long, monotonous march was made right away to the south-west, with the pile of rocks they had left gradually sinking till quite out of sight, and then, with the sun growing hotter and hotter, there was nothing visible on any side but the long, level stretch of sand.

The halt was not made till near midday, when the heat had become unbearable, and horses and camels were growing sluggish, and showed plenty of indications of the need of whip and spur.

Then, apparently without orders, the little knot of hors.e.m.e.n, led by the Baggara who had had charge of the prisoners, drew up short and faced round, when taking them as the extreme limit the rest of the train formed themselves up into a well ordered group as they came on, till, with the Sheikh's party and their guards as a kind of centre, and the camels with their loads behind, the hors.e.m.e.n closed them in as if for strategic reasons, and for the next half hour there was a busy scene, the camels being relieved of their loads as if the stay were to be of some hours' length.

This was evidently intended, for fires were lit and food was prepared, many of the hors.e.m.e.n after picketing their horses settling down at once to coffee and pipes.

It was while Frank and his friends were partaking of an _al fresco_ lunch, hastily prepared by Sam, that they had their first intimation of the Baggara chief being with the hors.e.m.e.n, for he cantered up to their temporary camp in company with his fierce-looking companion, leaped from his horse, and walked up to the Hakim at once, to give him a smile of recognition and hold out his left arm, which he tapped vigorously as if saying: "Look! Quite well again." Then turning round to the Sheikh he signed to him to approach, and said a few words hastily, before nodding to the Hakim again, returning to his horse, mounting, and cantering away.

"Well, Ibrahim," said the professor; "what does it mean?"

"That the chief's arm will soon be well; that the young chief his son will soon be well; and that the great Hakim and his slaves are to have no fear, for the Baggara are their friends."

"Yes, and mean to keep the Hakim and his slaves as prisoners as long as there are any cripples to cure," said the professor merrily.

"I suppose that is what it means," said the doctor quietly.

"That's it, sure enough," said the professor; "and we shall reach Khartoum, Frank, in half the time we should have managed it in if we had been left to ourselves."

Frank shook his head sadly.

"What! you doubt?" cried the professor. "Here, Ibrahim, what do you say to that?"

"His Excellency is quite right," replied the Sheikh. "We should have had to wander here and there, and have met with many hindrances by having to stay to perform cures of the sick people. Yes, it would have been a journey of many weary months."

"It will take much time now," said the professor, "but it looks as if we were really bound due south."

"I suppose there is a party of wounded men on the way?" said the doctor.

"Yes, they follow the chief's visits," said the professor. "My word!

learned one, your post is going to be no sinecure. Hah! here comes the first instalment."

For a roughly contrived litter was seen approaching, and directly after the chief's son was borne up to them by four of his followers and set down in front of the doctor, who attended to his patient, finding him no worse for his journey.

He was carried away again as soon as the Hakim had seen that his wound was healing well, and the arrival of the newly injured was expected; but none appeared, for the simple reason that the fresh tale of wounded was only imaginary, the Baggara chief, as was afterwards learned, having been successful in obtaining a large amount of plunder and many camels in his first raid after leaving the prisoners at the wells. These he had despatched under a small escort while he made for another village which had been marked down. Here, however, he met with a severe reverse, his men having to gallop for their lives, leaving their dead and wounded behind.

Hence it was, then, that the Hakim's burden became light for the rest of the march, which was continued day after day, week after week, till so slow was the progress that months had pa.s.sed and the despair in Frank's soul grew deeper.

The party were well treated, and won the respect of the whole force from the many kindly acts they were able to perform. For sickness was more than once a deadly foe which had to be fought, while help was often required after occasional raids made during the journey, in which the desperate dwellers in village or camp fought hard and mostly in vain for their lives and property, as well as to save those whom they held dear from being carried off as slaves.

"It is horrible!" Frank used to say. "These tribes are like a pestilence pa.s.sing through the land. The atrocities of which they are guilty are a hundred times worse than I could have believed. There can never be rest for the unfortunate inhabitants till they are swept away."

"Never," said the professor gravely. "The land will soon be one wide desolation, for the smiling oases where irrigation could do its part will soon be gone back to a waste of sand."

"And by the irony of fate," continued Frank bitterly, "here are we--so many English people, whose hearts bleed for the horrors we are forced to see--doing our best afterwards to restore to health and strength the wretches who have robbed and murdered in every peaceful village they have pa.s.sed."

He looked, and spoke, at the Hakim, as these utterances pa.s.sed his lips, and his brother's old school-fellow shook his head at him reproachfully.

"Don't blame me, Frank, my lad," he said. "I often think as you do, and it is only by looking upon the wounded men brought in as patients that I can get on with my task. Then the interest in my profession helps me, and I forget all about what they may have done. But I get very weary of it all sometimes."

"Weary, yes!" cried Frank; "but you must forgive me. It was all my doing, and I must be half mad to speak to you as I did."

"You are both forgetting why we came," said the professor quietly; "and between ourselves, you two, isn't it rather childish to talk as you do?"

"I don't know," said Frank impatiently; "all I can feel is that we seem as far from helping poor Hal as ever."

"Oh, no, we are not," said the professor. "We must be getting very near to the Khalifa's strongholds now, and we are going to enter with pa.s.s-keys, my lad. Once there, it will be hard if we don't find poor old Hal."