Crouch knocked out his pipe on the heel of his boot.

"Bravo," said he. "There's no question you should meet with success. If you get into the fort--as you think you can--you'll take their attention from the gate, and we ought to join you in a few seconds even if the canoe appears on the river. Still, it's a big risk you're taking; I suppose you're aware of that?"

"Quite," answered Max.

Thus was the matter settled; and soon afterwards darkness descended, and day turned to night in the course of a few minutes, for there is no twilight on the Line.

They took their places in silence under cover of the darkness, and then waited in patience and suspense. They had agreed upon midnight as the hour.

Max, lying upon his face in the sand which still retained much of the warmth of the day, followed the hands of his watch, which he was just able to see in the starlight. Never had he known time pa.s.s more slowly.

Even the second-hand seemed to crawl, and he was certain that the minute-hand never moved the thousandth part of an inch. And yet, at last the hour arrived. He knew that on the other side of the stockade both Crouch and his uncle were ready to advance. Rising softly to his feet he put his watch in his pocket.

On hands and knees he crawled forward to the ditch. He had decided not to enc.u.mber himself with a rifle. His revolver was loaded in his holster. He reached the ditch in safety, and there paused to listen.

There was no sound within the fort. The night was still as the grave.

Summoning his courage he rose once more to his feet, and laid hold with both hands upon the sharpened points of the stakes which formed the enclosure. Then, taking in a deep breath, he sprang, swinging himself on high, and landed on his feet on the other side.

A second later he stood with his revolver in his hand, glancing in all directions, ready to fire at sight. It was then that he stood in momentary expectation of a swift and sudden death. However, no shot was fired.

Seeing that he had entered the stockade and was yet undiscovered, he hastened into the shade of the nearest hut, and there knelt down and waited.

For five minutes he never moved, and during that time he heard no one either on the banquette or among the huts. Then he thought of Crouch and his uncle. He imagined the suspense which they endured. He realized that they must believe he had died in silence under the knife.

Presently, whether he fired or not, he knew that they would attempt to rush the gate.

It was, therefore, no longer necessary to remain undiscovered. It would aid their purpose better if some one saw him and he fired. His object was to create an alarm, to draw the attention of the garrison to himself, whilst Crouch and Edward, followed by the Fans, bore down upon the gate.

He stepped out from his hiding-place, and walked down the line of huts until he came to that which was Caesar's. He looked in. It was deserted, though a candle burned low upon the table.

At that he placed a finger round the trigger of his revolver, and fired three shots in rapid succession into the ground. Then, standing in the doorway of the hut, he listened.

Absolute silence reigned. The truth burst upon him as in a flash: the stockade had been abandoned. And at that moment there was a great crashing sound as the gate swung back upon its hinges, and Crouch and Harden burst into the fort.

CHAPTER XX--THE RATS ESCAPE

Edward Harden, rifle in hand, led the way, followed by Crouch and the four Fans. As they entered the stockade, expecting to be attacked from all sides in the darkness, they opened out in accordance with a pre-arranged plan. Crouch turned to the left and Edward to the right; and then, taking post on the banquette, they stood ready to fire.

For a few seconds there was absolute silence. The situation was so unlooked for that they could not, at first, realize what had happened.

Then Crouch's voice was lifted in the night.

"By Christopher, the rats are gone!"

Max, guided by the sound of these words, found the sea-captain in the darkness, and confirmed his suspicions. He said that he had been several minutes within the stockade, and had neither seen nor heard a living soul.

It seemed as if the valley of the Hidden River would maintain its reputation to the last. There was no end to mystery. Time and again were they confronted with facts that they were wholly unable to explain.

It was M'Wane who found a lantern in the hut which had formerly been occupied by de Costa; and with the help of this they searched the huts, one after the other, in the hope of being able to discover Caesar's line of retreat.

It was not possible that the Portuguese and his Arab attendants had left the stockade by way of the gate. By day, the garrison had been under the constant observation of their sentinel on the hills. Every night, as soon as it was sufficiently dark to permit them to approach, the stockade had been surrounded. They found nothing suspicious in any one of the huts, until they came to Caesar's, before which the yellow flag still unfurled itself upon the wind. Here they discovered that the ruby chest had gone.

Now, it would require four men, at least, to carry this heavy chest to the water's edge, and even then, the task could not have been accomplished without noise. It was impossible to believe that the garrison had pa.s.sed through the little investing force by dead of night.

And yet, as far as they could see, there was no other means of escape.

Caesar and his slave-drivers had vanished as suddenly and unaccountably as if they had been spirited away.

They separated and searched the stockade from end to end. It was M'Wane who gained the first clue, who came running breathlessly to Crouch.

"Master," he cried, "the wood-stack has been moved."

Within the stockade they had noticed on their arrival a great quant.i.ty of firewood, which had been cut in the adjacent forest. On approaching this, Crouch saw at once that the wood-stack had been pulled down as if in haste. Calling out to Edward to bring the lantern, he awaited further developments. No sooner had Harden arrived than the mystery was solved.

Leading downward into the ground was a broad flight of steps. A kind of tunnel had been formed under the sand, about four feet wide and six feet high, revetted by wooden beams. So all the time Caesar had been at liberty to escape, whenever he felt that he was sufficiently recovered of his wound to undertake the journey.

When Caesar had constructed his stockade in the heart of the wilderness, he had been prepared for all eventualities and had neglected nothing. He had unlimited labour at his disposal. Knowing the nature of his business, and the hatred with which he was likely to be regarded by the neighbouring tribes, he had thought it likely that, at some future date, he might be called upon to undergo a siege. That siege might last for several months, by which time his provisions would be exhausted and he obliged to retreat. As far as they were able to discover, the subterranean pa.s.sage had been made during the absence of de Costa on a two-months' journey to the Coast, in order to procure fresh supplies of dynamite. From the fact that the half-caste knew nothing whatsoever of the pa.s.sage, it seems likely that the Portuguese had all along intended to desert his companion at the eleventh hour.

Without a word, Edward Harden descended the steps, holding the lantern on high to guide his friends who followed. The pa.s.sage lay in a bee-line throughout the whole of its length. It was about three hundred yards long, and whilst it ran through the sandy sub-soil in the crater of Makanda, both its walls and roof consisted of solid logs. For the last hundred yards it pierced the living rock, and at last came forth in the impenetrable darkness of the forest.

By the aid of the lantern they were able to discover a path which led to the left, and after a few minutes' walking, this brought them to the river bank. Here, in the soft mud, was the indentation of the bows of a canoe. Moreover, the place was so screened by trees and tall reeds that no one, pa.s.sing either up or down the river, would suspect for a moment that here was a mooring-place. It was here that the "phantom canoe" had lain, to be brought upstream by two or three of the Arabs from the stockade on the night of the attack.

No sooner did Crouch observe this evidence of the means Caesar had taken to escape, than he shook his fist in the air.

"He's gone down-stream," he cried. "But, I'll follow him, if he leads me a ten-years' journey through the wilderness. I'll overtake that man, and I'll kill him. I swear it. I swear that I'll never set eyes upon the sh.o.r.es of England again, until I know that he is dead."

And that was the oath of Captain Crouch, which--when we have got to the end of the story--will prove to us that oaths are very futile after all.

The strength of man is limited; in face of the wonders of the universe, his knowledge is indeed small. He may be strong and brave and unswerving of his purpose; but, after all, where men teem in cities, no less than in the heart of the illimitable and mighty forest, there is a greater Power than anything that is human--the all-pervading Spirit of the Universe, before whom the foolish vows of men are of infinitesimal account.

Crouch had flown too often in the face of Providence not to be aware of that; but, just then, he was well-nigh mad with wrath and restless with excitement. s.n.a.t.c.hing the lantern from Edward's hand he raced along the pa.s.sage, until they found themselves again within the stockade.

Still, the captain never paused. He pa.s.sed through the gate, and thence ascended the hills. They found the slave-camp absolutely silent. On every hand the unhappy negroes lay stretched upon the ground, and there in the middle of them was de Costa, nature striving to maintain the spark of life within that fever-stricken body, by means of healthful slumber. On the eastern horizon, beyond the unknown hills which they had seen from Solitude Peak, the dawn was rising in a flood.

With scant ceremony Crouch awakened first de Costa, then every one of the slaves. Through the medium of the half-caste he spoke to the natives as follows--

"We found you slaves, we have made you freemen. Are you grateful for what we have done?"

A murmur arose from the crowd. They said that they were mindful of what they owed to the white wizard and his brave companions.

"Then," said Crouch, "you can help us. We are going down-river. We must start at once. We must take all our baggage, our stores and ammunition. There are six canoes at the kraal, and these will be sufficient. But we will need porters to make the journey through the jungle to the Kasai. If you come with us, to carry our loads and canoes, we will pay you in cowrie sh.e.l.ls and beads, bra.s.s rods and cloth."

To a man they volunteered, and not five minutes later a caravan of fifty carriers, protected by seven rifles, descended to the lake before Makanda.

In less than an hour the canoes were loaded, and then the expedition shot down the stream, the canoes following one behind the other in single file. Crouch led the way, his quick eye sweeping either bank in search of the place where Caesar had embarked. Max, in the last canoe brought up the rear.

As the canoes gained the point where the sandy plain around the settlement gave place to the density of the jungle, all turned and looked back upon Makanda. To the slaves, many of whom had worked for two years under the whip, without hope of ultimate salvation, it was as if they looked their last upon their prison doors. As for the Englishmen, they remembered that grey, steaming morning when they had first come within sight of the stockade, when Caesar had fired at them from the water.

All that had happened in the weeks that followed was like some strange, swift-moving dream.

It was midday when they reached their old camp at Hippo Pool, and Harden and Crouch disembarked, to see if they could find traces of Caesar's escape on the line of their former portage.