“It’s queer!” said Venning.  “Where is the water?”

On looking around, they beard for the first time a peculiar subterranean rumbling, and going back a few feet, saw the river disappear in a smooth, green slide down into a wide fissure.  They stood looking down, fascinated at this mysterious, silent, and stealthy disappearance of the waters that come with such a sparkle out of the bright valley; then dropped stones down, and stooped their heads in vain to catch even the slightest sound out of the depths.  The fissure was about twenty feet wide, with a sloping lip on the near side, and a straight wall on the far or forest side.  The slope seemed to carry the water to the left, and with a desire to discover its course, they tugged at a large post which stood against the wall of the gorge and rolled it into the fissure.  It whizzed away down into the dark, and nearly dragged Compton after it, for the sleeve of his coat caught on a projecting point, and he was jerked on to his knees, being saved from further danger by the coat tearing.

“Thanks,” he said, looking a little white; “I am quite satisfied that the water disappears.”

“I rather think,” said Venning, “that we have pulled up a gate-post.  See, there is one on the other side.  A few tree-trunks thrown across would make a fine barricade.  Come on back into the valley.”

They went back slowly, looking up at the dark walls of the rocky gorge, and Venning stopped.

“See that rock up there?”

“Looks as if it would drop at any moment.”

“Remember what Muata said about Hassan drowning out the valley.”

“One of his figures of speech.”

“S’pose that rock fell; it would just about fill up this passage, river and all.  And if it did not quite, a few men working from the ledge, which you see would be behind the dam, could easily fill up the cracks.  Then the river could be dammed and the valley flooded.”

“They’d have to blast the rock, and the task would be too troublesome.”

They returned slowly through the defile, stopping at the place where the warrior had sprung out on Compton, and on reaching the valley, went down among the rustling bananas and among the gardens, where the women stopped their work to shout out merry greetings, and to offer them earth-nuts, wild cherries, sweet cane from the maize patches, and a thick porridge-like beverage made from the red millet.  They watched the little pickaninnies basking in the sun, and as they strolled, rejoicing in the brightness and in the beauty of this little island of rest, set within an ocean of trees, they were followed by an admiring company of lads, each carrying his hurling-stick.  Coming to a little patch of reeds in the far corner of the valley, the black boys, with shouts, gave chase to a long-tailed finch, clothed in a beautiful waistcoat of orange.  The two white chiefs threw aside their dignity, and when, after a breathless chase, the bird, hampered by its streaming tail-feathers, was caught, each chief stuck a feather in his hatband.  They worked round the valley, seeing many strange birds and curious insects, back towards the cave, arriving on the ledge at dusk.  At once they opened out on Mr. Hume with a description of where they had been and what they had seen.