“As you wish to keep us here,” he said, “we will stay here; and, take notice, we have already seen what was in the mind of the chief by taking steps to protect the entrance above the tabooed water.”

The chiefs mother desisted, but she went up to interview the two young chiefs.

“The great one,” she said, “has very strong medicine?”

Compton nodded his head gravely.

“He was consulting with the spirits in the night when he sent forth those fire-devils?”

Another nod.

“Wow!  And the spirits told him to build a wall across the entrance, and to make a fence across the river?”

“That was wisely done, as you see, mother.”

“Haw!  Tell me why the spirits told him to move the village to a place which is further from this cave;” and she looked through narrowed eyes.

“Ohe!” said Venning, “that was also wise.  The old village stood on low ground, the new village is on high ground.”

“And a tall man sees over the head of a small one,” she answered, with a scornful laugh.

“Wait, mother of wisdom.  If the enemy secured the gates and flooded the valley, which would be safer—­the village on low ground, or the village on a hill?”

“Yoh!  It is strong medicine.”  She sat looking at them for some time in silence.  “It is only the great one who can make medicine?”

Compton looked thoughtful.

“Come,” she said, in a wheedling tone, touching him with a finger, “make medicine for one who carried food to the good white man.”

“What would you like to know, mother?”

“Tell me, O son of him who taught us—­tell me, O lion’s cub—­tell me if the chief will find his own kraal.”

“That would need strong medicine—­very strong.”

“Only a little.  Consider; it was these hands who carried the good white man water and wood.  Only a little word, his son.”

“A little word, mother; but it requires much thought, and how can a son make medicine without his father’s ’familiar’—­the thing he consulted, the thing you promised to bring to me?”

“I will fetch it,” said the woman, rising.  “In the morning you shall have it;” and she went in the direction of the gorge.

“Seems to me, Dick, the old lady is at the bottom of this mystery.  You’d better be very careful how you deal with her.”

“I want to get my father’s book,” said Compton.

“Of course you do; but you want to get back the Okapi as well, and if you offend her it may turn out more awkward for us.”

“Well, then, suppose we follow her now?” and Compton, always ready to act, jumped up.

“What’s the good?  Remember how she spotted Mr. Hume the day he ‘blazed’ the trees.  Believe she’s got eyes in the back of her head.  No; but I learnt a trick from a keeper in dear old Surrey that will do what we want.”

In the dusk Venning put the trick into effect with the help of his companions.  It was simple enough.  He drew fine linen threads from a handkerchief, stained them black and stretched them across the track down the gorge at five different intervals, and at the height of a few inches from the ground.