One glance was sufficient to tell the merest novice in such matters that this cavern had at some distant date formed the channel of one of those underground rivers by no means uncommon in Africa. What had been the bed of the stream was, however, filled in with earth, and was now to all intents and purposes a very passable road, which, after mounting a short hill that served in fact to keep back the water from the basin, ran straight before them as far as the light could penetrate.
The first act of the whole party was to remove themselves from the intense heat thrown out by the gas; their next, to draw their pistol-cartridges and slip fresh ones into the chambers; and hardly was this done when a startled exclamation, uttered just behind them, caused all to turn hurriedly, only to find themselves confronted by a most repulsive-looking white man, who stood dripping unpleasantly upon the rocky ledge and regarding them with a scowling face.
The newcomer appeared altogether unarmed, and our friends promptly rushed at him; but he incontinently turned tail, and dived out through the entrance, followed like a flash of light by Myzukulwa.
The cousins waited in anxious suspense for close upon a minute, and then the great Zulu silently appeared upon the rock and lay gasping for breath. Soon, however, regaining his wind—
“Inkoos,” he said, “he was too quick for me; the coward ran away down the pass; but first he fired his gun, and it was answered by another gun a mile away.”
It was quite clear that the man had been a sentinel near to their old sleeping-place, and, seeing the Fall suddenly light up of its own accord, had come down to examine the unusual phenomenon.
The three now fell to eagerly discussing their position. If they were holding the only entrance to the passage, they could with their revolvers defy almost any number of men attacking through the water; but if, on the other hand, there was more than one way of access to the cave, or if another hostile body, attracted by the firing, should come up the river Pass, our friends would be placed between the devil and the deep sea with a vengeance.
Then, again, if the foe had any means of extinguishing the light from outside, the trio would be entirely at their mercy.
This light was evidently a pure gas generated in the mountain, and used by these strange people to light them to the entrance of the cave; but how they extinguished it, and how without its help they followed their subterranean road through the absolutely inky gloom, was a mystery to the adventurers.
On looking about, however, they discovered a bundle of torches made of a resinous woody fibre, and lighting one of these in the gas-flame, Grenville proceeded to examine the road and see what cover, if any, it might offer. Hardly had he taken a dozen steps when a stream of water poured through the fissure in the roof of rock, extinguishing the gas in an instant. Grenville quickly whispered to his friends to bring the torches and follow him, as without proper light to shoot by it was impossible for them to hold the entrance to the passage. “Bring every single torch you can find,” he said, “and keep your eyes skinned for any more lying about the road. We’ll keep these beggars in darkness if possible; and once let us get to daylight, and we’ll fight them if need be.”