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.
He noticed a clump of trees a little to the right, nearer the bank of the river, and made straight for that. As he ran towards it, he came within view of the horsemen working round on the left flank. They immediately wheeled round, and galloped hard in pursuit.
But their course brought them below the ridge on which, all unknown to them, Challis and his band lay concealed. As they rode past, within range of about a hundred yards, a sudden volley on their right flank sent some of them reeling to the ground. The rest, taken all aback, swerved to the left, and dashed frantically away towards their main body, who had now become aware that the hillock was deserted, and were surging up it.
"Well done, Tom!"
The ringing words came faintly from the rear. Challis brushed his sleeve across his sweating brow, and ordered his men to run with him.