The Hausas kept absolute silence, awaiting their leader's command. It came when the Tubus were no more than two hundred yards distant. The rifles flashed; several of the horsemen fell; some halted behind the largest bushes near to them; others turned and galloped to the shelter of a clump of trees. Royce rose on his knees, and peering over the brushwood, anxiously scanned the farther bank up and down stream. In both directions the flanking movement was continuing, and what was more serious, in response to a mighty shout from Goruba, whose tall form could be seen threading its way between the bushes in the distance, the Tubus dismounted, and tethering their horses, began to work their way forward on foot. Royce tried to pick off the leader, who was clearly something of a strategist. But the negro took such skilful advantage of the bushes that Royce was never able to get a clear shot at him. His intention was obvious. It was to hold the party in front, while his men crept round on each flank, and enveloped them. "We run the risk of being surrounded," Royce called to Challis at the other end of the line; "there's nothing for it but to retreat." To retreat, even with a disciplined force, is, as Royce knew, one of the most hazardous operations of warfare. The risks were tenfold with his Hausas, none of whom had served in the West African Rifles, who have become such excellent soldiers under the training of their British officers. But they were a compact little band, all devoted to him, and he decided to take the risk. First sending word to the unarmed men to make all speed to the rear with their loads, he divided his little force into two parties. "You see that ridge yonder?" he said to Challis, pointing to a bush-covered position some distance away. "Fall back to that slowly with your lot. I'll join you as soon as I can." Challis set off. Meanwhile Royce retained his position, and kept up a steady fire on the enemy as they advanced, creeping on yard by yard under cover of the bushes. "Whenever you see a man, shoot!" said Royce to the Hausas. "Don't shoot without marking your man." The Tubus made no use of their firearms. Royce and his men were hidden from them by the brushwood, and they did not waste their shots on an enemy whom they could not see. No doubt, Royce reflected, this was a mode of warfare to which they were unaccustomed. They were used to carry all before them in a dashing charge, and he wondered at their persistence under the new conditions. Presently a shrill whistle from the rear announced that Challis had taken up his position on the ridge. The space between was a long undulation, only a few yards of which, at the rearward end, were in view of the enemy. "Now, boys, run!" said Royce. Heading his men, he sprinted down the incline, rushed up the farther acclivity, and dashed past Challis and his party, calling to Challis to hold the Tubus until he had gained a new position still farther to the rear.