soft moist air which seemed so different from the dry,
harsh, parching wind of the desert. There was the pleasant scent of
growing plants, too, rising from wherever the overflow from the
fountains permeated the sand, quite unseen in the broad sunshine, but
showing its effect in a blush of green which gradually grew less and
less, till at a few hundred yards from the rocks and pools it died right
away and all was arid barrenness once more.

Now and then a wailing howl came from a distance, to be answered here
and there by the prowling animals which scented the food of the camp,
and hung about waiting till the caravans had passed on to make a rush in
safety for the scraps that were left, with the result that the
neighbourhood of the pools and wells was found free from all refuse by
the next comers.

The Hakim's party was too weary with the nervous excitement and hard
labour of the past day to talk much, finding it pleasanter to sit or
recline and listen to the various sounds that reached their ears from
the Baggara camp or far out in the desert, till after being absent for
some little time the Sheikh came softly up to the tent and waited to be
questioned. He did not have to wait long, for the professor attacked
him at once.

"Well, Ibrahim," he said, "what news?"

"Little, Excellency. The Baggara have sentries out all round the camp."

"And ours?"

"Yes, Excellency; we are prisoners."

"But in no danger?"

"No, Excellency. It is peace between us and the fighting men. But if
they are attacked in the night or just before daybreak we are in bad
company, as you would say, and we shall perish with these tribesmen if
they are beaten."

"That sounds bad," said the professor. "But look here, who is likely to
attack their camp?"

"Who can say, Excellency? Like the people of old, their hand is against
every man, and every man's hand is against them. They are wandering
about harassing villages, plundering, and making slaves. Some of the
village people may take heart and join together to slay them; or the
Khedive's men may hear of their being in the neighbourhood, and come
from boats upon the river. There may be soldiers of your own journeying
south, who, hearing from spies that a party of the Khalifa's men have
come so far north, would be sure to try and scatter them like the sand
before the storm."

"But, on the other hand," said the doctor quietly, "none of these things
may happen, and we may sleep in pea