Some hours later, after making good time in the cool of early night, the travellers began to work clear of the low thorn-bush, and emerged into open, somewhat mountainous country. Clifford was travelling west now, and travelling fast; feeling his way over the country to some distant prearranged destination. Saidi, the expert guide, was out in the lead—for no white man has eyes or hearing equal to the black in his native country. Both travellers were dismounted and led their mules. They wound their way through tall valley grass, breast high and dust-laden; over pools of mud, long sun-baked and waterless; then out, finally, on to rising ground strewn with lava rock and volcanic boulders. It was weird wilderness country, barren of habitation—virgin and waterless as on the day of Africa’s dawning. The night progressed uneventfully. Nothing suspicious was encountered. No tracks of the cattle raiders were crossed. The air was breathlessly still, and it was oppressively hot in the valleys. Toward midnight the waning moon drooped lower and lower on the horizon—and went out. Travelling then became slower and more wary; occasionally man or mule stumbled over a boulder painfully and noisily in the breathless darkness. No conversation passed between man and servant. Tirelessly they padded on, each certain of the other’s knowledge almost as animals are certain of the bypaths to their lair. For them the night held little mystery. They were startled not by the grim silhouettes of zebra, or hartebeeste, when, at a dozen yards, they chanced upon game herds which galloped off into the night like riderless squadrons. Nor did the whir of wings and frightened cackle of guinea-fowl, disturbed at their very feet, more than startle the mules to one brief backward jerk of their bridle reins. Day was dawning when Saidi, who had for some hours been following an obscure track through the dark with his lynx eyes, gave a grunt of satisfaction as a gap loomed visible between two dull grey hills in front. Soon they entered a narrow pass and prepared to make camp in the hidden cavity between the hills. Here was water, and camp, and the first halt in the march; for a dry rocky river-bed, cut by the torrents of the brief rainy season, ran down the pass, and there, in a deep pocket in the solid rock, worn smooth and circular as a gigantic porridge pot, was a pool of water, green-slimed and stagnant, it is true, but priceless, nevertheless, in the sun-parched desert. The mules were off-saddled, rubbed down, and fed; and picketed under cover of the hill-side—for they were now in country where the raiders might be encountered, and every precaution was being taken to lie low and outwit the enemy.