Jack felt himself turn pale as he heard this. The facts were coming home to him. The thought that little Bakota, the chubby boy whom Barney employed to wash dishes, or little Ilangala, the girl whom the same indefatigable factotum had taught to darn his socks, might fall into the hands of these ruthless cannibals, to be torn limb from limb, and sacrificed to their brutal appetites, kindled emotion within him much more poignant than the mere report that such things had happened in the collection of rubber on the Congo, somewhere, at some time.
He dismissed the man under guard, and went to his hut, wishing to be alone. An hour or two later Lepoko came to him; the prisoner had given more information.
"Him say, sah, big massa lib for come back up ribber. Him say Elobela no let massa come to Ilombekabasi; catch him, sah."
Here was a new source of uneasiness and anxiety. Jack had longed for his uncle's return; now he almost wished that something had happened to prevent his departure. Already he had had such proofs of Elbel's vindictive and unscrupulous temper that he dreaded what might happen should Mr. Martindale fall into his hands. But for the moment he saw no means of warning his uncle, and he tried to crush his fears and forebodings.
During the next few days several of Elbel's scouts were killed or wounded by Jack's men, who had so far been wonderfully successful in escaping injury. One man of the enemy who was brought in wounded confirmed the first prisoner's statement that the Inglesa was said to be on his way. The river was being watched at various points of its course, and Jack recognized the hopelessness of attempting to evade these sentinels and give his uncle timely warning.
Ten days had passed since the stream had been diverted, and the last captured scout said that Elobela was growing very impatient. He could not understand how the fort had been able to hold out so long. Every day he expected to see a flag of truce hoisted, and to receive a message asking for the terms of surrender. One evening another scout was captured, and from him Jack learnt that his secret had at last been partially discovered. Angry at being so long baulked, Elbel had determined to find out the source whence the defenders obtained the water he knew they must have. He sent out scouts for this express purpose. One of them, creeping up the bed of the stream below the southern face of the fort, had discovered that the precipice, which from a distance looked dry, was running with water, and that a thin stream was trickling into the gully. The ground had gradually become saturated, and the overflow, which had at first disappeared into the earth, was now making itself only too visible. When the discovery was reported to Elbel, he concluded that there must be a spring within the fort. Great was his fury at having wasted so much time and labour fruitlessly. In his anger he declared that the defenders should have plenty of water in future.
"What did he mean by that?" asked Jack.
The man did not know. Elobela did not tell all his purposes to the black men.
The very next morning it was observed that a large body of men was again on the move up the hill. Jack hurried to the top of the north-west blockhouse and followed the movements through his field-glass. This time an even larger force was engaged than had been previously employed to dam the stream. Two parties, riflemen and spearmen, numbering in all, as he estimated, nearly six hundred, were marching up the heights. Clearly some new work was to be undertaken, and it must be of no little magnitude. There were no signs of preparation for an immediate attack. The troops continued their upward march for at least a mile. Then Jack was surprised to see them set to work rolling boulders down the hill towards the slope at the north-east of the fort and the new course of the river. Whatever the scheme was, it involved a great deal of labour, for the whole day was spent upon it, and still the parties of workers had made but small progress down the hillside. It became clear to Jack that the supply of boulders lower down had been used up in constructing the dam. More boulders were evidently required, and to procure these Elbel had had to take his men a considerable distance up the hill.
Late in the afternoon the negroes were marched back to camp. As soon as it appeared safe, Jack sent Samba out to ascertain what had been done. When he came back he reported that a large quantity of stones had been collected near the dam, and that though the main body had returned to their camp, there were still several large parties engaged in hauling boulders nearly a mile away from this point.