Without hesitation, and as if the action was perfectly natural to him, the lad moved till his body shielded his chum's face from the now strengthening rays of the sun. "The youngster's learning his lesson, poor chap!" thought Mr. Reeves. "I remember him at home as a selfish, unthinking little prig. Already he's beginning to think of others." The camp was soon astir. The camels, horses, and cattle were taken out to the wells--mere dipping holes of brackish water--and afterwards allowed to graze upon the scanty pasturage of sun-scorched grass. Ere the disturbed water had been given time to settle, a fierce-looking Baggara, armed with spear, short knife, and circular shield of hide, made the captives go to the wells and drink. Both lads remembered how careful Mr. Frazer had been to warn them about drinking unfiltered water. The fountain water of Naples was perfect nectar to this muddy liquid, but thirst compelled them to drink deeply in spite of their qualms. "I wish we could place our hands in the pool," said Gerald. "You'd be sorry if you did, my boy," replied Mr. Reeves. "The moisture would cause the leathern thongs to shrink, and they are quite tight enough already." "Are we going to be kept long in this place?" asked Hugh. "That I cannot say," replied the correspondent. "Perhaps only a day. The Arabs will make another march to-night, I believe." Thoughts of the impending separation were still uppermost in his mind. He was torn by the vital question: Ought he to warn the lads? On the one hand, being prepared is forearmed; on the other, he was adding to their miseries by suggesting a situation that might not, after all, come off. It was like meeting trouble half-way. Then he recalled the sheikh's words, "the white unbeliever who was brought from the south". The south? What European was likely to have traversed the vast, trackless desert of Sahara from the south? Nigeria, the Cameroons, French Congo--all lie to the south; but was it possible that a white man could make that fearsome journey? But perhaps the south was a term used in a vague, elastic sense, and the captive referred to was a survivor of the prisoners of the Mahdi? Reeves determined to keep his ears open, and for the present he would say nothing to his young comrades about the conversation he had heard between the Sheikhs Wadherim and Abdullah. "Look here, boys!" he exclaimed; "I may want you to do something. What it is I won't tell you at present, but you must act immediately I give the word. You understand?" For a wonder, Reeves remarked, neither of the lads asked why. Both signified their readiness to comply with their friend's instructions.