It will be remembered that it had taken two and a half days to make the journey to Makanda from Hippo Pool. They returned in seven and a half hours, and even then the natives did little work with their paddles.

The fact was that, from the granite hills that almost surrounded the station of the Portuguese, a number of small tributaries joined the Hidden River. In consequence, a great volume of water flowed down to Hippo Pool. The current became stronger every mile, since the banks grew nearer together, and several jungle streams joined forces with the river. The largest of these was the tributary which flowed into Hippo Pool, along which had lain the latter part of the portage they had made from Date Palm Island on the Kasai. Harden named this stream Observation Creek, for a reason which we are just about to explain.

They camped on the east bank of Hippo Pool, at a place selected by Crouch. Two courses lay open to them: they had either to remain here indefinitely, or, leaving their canoe on the Hidden River, to return to Date Palm Island by the route of their former portage. Never for a moment had they had any intention of returning to the Kasai until they had discovered something more definite concerning the mystery of Makanda. That night, seated around their camp-fire, by the waters of Hippo Pool, they held a council of war.

With this place as their base, they were resolved to operate against CÆsar's position farther up the river. That afternoon, M'WanÉ had climbed to the top of a gigantic cocoanut-tree, some little distance from the right bank of Observation Creek. Thence he had surveyed the surrounding country, and it was largely on the information supplied by M'WanÉ that Edward Harden drew up the sketch-map which proved so useful to them throughout the eventful days that followed.

From that tree-top the broad course of the Kasai had been visible, its gleaming waters showing here and there, white in the sunlight, to the north and to the east. To the north-west, the course of the Hidden River lay comparatively straight to the mangrove swamp where it joined the larger stream. The rapids began three miles or so below Hippo Pool, and there, according to M'WanÉ, the river was foaming white. Lower still, it entered the Long Ravine, where great bare cliffs rose upright on either side, and at the end of which was the waterfall of which the Fans had spoken. On some days, when the wind was from the north, they could hear the dull roar of the cataract, like thunder in the distance.

To the south-west, above the tree-tops of the forest, M'WanÉ had been able to observe the crest-line of the red granite hills which enclosed the station of Makanda. Almost due south, from out of the midst of the forest, like a giant in a stubble-field, a great mountain towered into the sky. On the northern slopes of this mountain the Fan chief had been able to discern a little village, lying like a bird's nest in a declivity, thousands of feet above the dark, inhospitable forest. One night, by firelight, on the banks of Hippo Pool, Edward Harden drew the map on a piece of cartridge paper, though many of the features thus shown were not filled in until further facts had come to light.

Their plan of campaign was evolved in the fertile mind of Crouch, though Max, and even Edward, made several suggestions which the little sea-captain was only too glad to accept. They named the mountain Solitude Peak, and it seemed probable that it was in this direction that the creek found its source.

They desired, if possible, to reach Makanda without the knowledge of CÆsar and his Arabs. They did not doubt that they would be able to overlook the stockade from some eminence in the eastern granite hill. Now, since it was two and a half days' journey up the river, it would take them months to force their way through the jungle to the south. They decided, therefore, to follow Observation Creek to its source, which, they hoped, would be somewhere in the vicinity of the mountain. There they might be able to glean some knowledge at the native village which M'WanÉ had seen in the distance. At any rate, they would be able to survey the surrounding country, and take the most accessible route in the direction of Makanda.

However, neither Crouch nor Harden was the man to undertake anything rashly. Each knew that in CÆsar they had an adversary who was not to be despised. Before they set forth upon their expedition, they decided to secure more ammunition and supplies from Date Palm Island, and for this purpose it was decided that Edward Harden should return to the Kasai with M'WanÉ and the Fans.

Accordingly, the next day the explorer set out, following the route of their old portage along Observation Creek, and thence through the jungle to the left bank of the great river opposite Date Palm Island. Edward thought that he would be able to persuade the Loango boys to carry the "loads" back to the base-camp at Hippo Pool. Then, if they still feared to remain in the valley of the Hidden River, they could return to the Kasai. That night, Crouch and Max were the only two who remained at the little camp at Hippo Pool.

The next three days were by no means idle. Game had to be shot in the forest; there was cooking to be done; they even carried the canoe ashore and repaired a small leak which had been sprung in her bows. Moreover, Crouch insisted that one or other of them should always be on watch. With a good fire burning throughout the night, they had little to fear from wild beasts. Even the leopard, which is a far more courageous animal than the lion, must be well-nigh starving before it dares to approach a camp-fire. What Crouch feared most was a raid on the part of CÆsar. He knew enough of the tall Portuguese to suspect that the man would not stay idle whilst the three Englishmen remained in the valley of the Hidden River. In one of the many canoes they had seen tied up to the river bank at Makanda, CÆsar could shoot down-stream in the space of a few hours. There was therefore not an hour of the day or night that one or the other of them was not seated on the river-bank, rifle in hand, with his eyes turned towards the southern extremity of Hippo Pool.

Three days passed, and nothing of importance occurred. It was on the third night that something happened which was so much in the nature of a mystery as to be fully in keeping with the character of the whole valley and the rumours they had heard. Though Captain Crouch had only one eye, that eye was as the eye of a lynx; and the matter in question is all the more worthy to relate, since the event first occurred by night, when Crouch himself was on guard.

That day Max had shot his first buffalo, about half a mile from camp, on the southern side of Observation Creek. The meat had been cut into steaks, and one of these was cooked that night for breakfast in the morning. Crouch relieved Max on sentry at twelve o'clock, with the intention of keeping watch till daybreak. As Max turned over to go to sleep, he distinctly remembered having seen the buffalo-steak on a tin plate, a few inches from the fire. In the morning this steak was gone.

Crouch had seen nothing. He was prepared to swear that he had never been to sleep. Throughout the morning the matter seemed to worry him a good deal.

"I can't make it out," he said, talking to himself, as was his wont. "I don't believe any leopard would do it. The beasts are terrified of fire. A starving leopard might; but no leopard could very well starve in a valley like this, which positively abounds in game." At various intervals throughout the day he gave expression to the same opinion.

That night Max took the first watch, from seven o'clock to twelve. During that period never once did he relax his vigilance. He sat, hour by hour, with the fire at his elbow, and his face turned towards the river. He was thinking that it was nearly time to awaken Crouch, and had pulled out his watch, when he heard the sound of a breaking twig a few feet behind him.

He turned sharply, and was just in time to discern the shadow of some great beast disappearing into the jungle. His eyes shot back to the fire, and there he beheld to his amazement that once again their breakfast had disappeared. He immediately awoke the little sea-captain, and told him what had happened.

"Did it look like a leopard?" asked Crouch.

"No," said Max, "I think it was a lion."

Crouch got to his feet.

"I don't believe it," said he. "The king of beasts is the greatest coward I know. The most courageous animal in the world is the African buffalo, and after him come the peccary and the wild boar. All the cats are cowards, and the lion the biggest of all. Once I was shooting buzzard on the Zambesi, when I came face to face with a lion, not fifteen paces from me. I had no one with me, and was armed only with a shot-gun. What do you think I did?"

Max laughed. "Ran for it?" he suggested.

"Not a bit!" said Crouch. "That would have been sheer folly; it would have showed the brute I feared him. I just dropped down on all-fours, and walked slowly towards him."

"Great Scott!" exclaimed Max, unable to restrain his admiration.

"That lion," said Crouch, "looked straight at me for about three seconds, and then quietly turned round and walked away, swishing the flies from his body with his tail. As soon as he thought he was out of sight, he broke into a gallop. It was beneath his dignity, I suppose, to let me see he was frightened. He had got to live up to his reputation."

"Is that actually true?" asked Max.

"As true as I'm standing here. All lions are naturally frightened of anything they can't understand. That particular animal couldn't make me out, didn't like the look of me; so he just walked away. The lions in this valley can have had little or no experience of white men. I therefore refuse to believe that our breakfast has been stolen by a lion. Shall I tell you who I believe is the culprit?"

"Who?" asked Max.

"Gyp," said Crouch; "CÆsar's dog. CÆsar himself could hardly have got here by now. Yesterday afternoon I reconnoitred some way up the river, and saw no signs of a canoe. But the dog could have found its way through the jungle. It seems improbable, no doubt; but I can think of no better explanation."

Indeed, this was the only solution of the matter, and they resolved to be upon their guard.

The following day they determined to explore the rapids. They were already acquainted with the river-valley between Hippo Pool and Makanda, but as yet they knew nothing of the country which lay between their camp and the mangrove swamp on the Kasai. M'WanÉ, from the cocoanut-tree, had caught sight of the Long Ravine, which ended in the waterfall of which the natives had told them, the dull roar of which was frequently audible at Hippo Pool when the wind was in the right direction. They did not expect Edward back for some days, and each was of the disposition that chafes under the restraint of inaction.

Accordingly, soon after daybreak they launched the canoe, and taking with them three days' supplies and a quantity of ammunition, they shot down-stream to the north. The descent of the river was easy enough. Throughout the journey Crouch kept his eye on the current. Since this grew stronger and stronger as they progressed, he did not desire to go too far, knowing full well that the return journey would be by no means easy to accomplish.

At a place where the river was exceedingly narrow, and the jungle on either bank even more dense and tangled than usual, they heard, on a sudden, the crashing of undergrowth in the forest, as if some great beast were flying for its life. A moment later a leopard sprang clear from the river bank. For a second the beast was poised in mid-air, its legs extended at full length, its ears lying back, its superb coat dazzling in the sunlight. Then it came down into the water with a splash.

For a few strokes it swam straight for the canoe. Max carried his rifle to the shoulder and fired. The beast was hit, for it shivered from head to tail, and then turned round and swam back to the bank whence it had come. As it crawled forth, dripping, with its head hanging low between its fore-legs, the great snout of a crocodile uprose from out of the water, and the huge jaws snapped together.

Crouch, who was steering, ran the canoe into the bank, and a moment later both he and Max, their rifles in their hands, had set out into the semi-darkness of the jungle.

They had no difficulty in following the leopard's spoor. The beast was badly wounded and very sick. Every hundred yards or so it lay down to rest, and when it heard them approaching, rose and went on with a growl.

Presently it led them into a marsh--which Edward Harden afterwards called Leopard Marsh--where they sank knee-deep in the mud. There were no trees here. In the middle of the marsh, lying in a few inches of water, was the wounded leopard, wholly unable to rise.

"He's yours," said Crouch. "I'll stand by in case you miss."

Max lifted his rifle, took careful aim, and fired. On the instant, with a savage screech, the leopard rose with a jerk. For a moment it stood upon its hind-legs, rampant, its fore-feet fighting in the air. Then it came down, as a stone drops, and lay quite still.

Max felt the flush of triumph that every hunter knows. His blood tingled in his veins. He was about to rush forward, to gloat upon his prize, when from somewhere near in the forest a shot rang out, and a bullet splashed into the moist ground at Max's feet.