d creatures, which rapidly
grew into shapeless monsters writhing their long necks and snaky heads
as seen in the darkness, till they looked like nothing so much as the
strange fancies indistinctly seen in some feverish dream.

So well had the preparations been made that an hour amply sufficed for
the loading up, and at the end of that time the two troops of camels
were standing, each with its own drivers, a short distance apart, and
nothing remained but for those who rode to mount and the order to be
given for the start.

It was just then that a tall, dark object, the one for which the doctor
had been anxiously looking, loomed up from the Baggara camp and stalked
silently up to where the Baggara chiefs son lay waiting upon his rug.

As it reached his side, attended by two men, the great camel was
stopped, and its load was more plainly to be seen, shaping itself into a
couple of rudely made, elongated panniers, out of one of which, while it
was held, a man leapt lightly out, the other being occupied by one of
the weakest of the wounded.

The doctor and Frank then superintended the lifting in of the chiefs
son, who bore the movement without a sigh, and the great camel, after
the rug had been laid across like a form of housing, was led back to its
fellows, some twenty yards away.

Then from out of the darkness an order rang out, and the waiting camels
were mounted, after which there was the snorting of horses, and half a
dozen graceful creatures trotted by to take the lead as advance guard,
the troop waiting till they were a little distance ahead. At last the
shadowy looking line of camels, horses, and men were awaiting the order
to start, for some reason unaccountably delayed, when suddenly the
Sheikh laid his hand upon Frank's arm.

"Hark!" he whispered excitedly. "Listen! Do you not hear?"

Frank shook his head.

"It is quite plain," continued the Sheikh. "Horses--the trampling of
many men. Keep close together, Excellencies, while I warn my people."

"Warn them of what?" said the doctor calmly.

"Danger, Excellency. These may be friends coming, but it may mean an
attack or the coming of strangers. If it is either of the latter I
shall try to lead you all into safety. So at a word follow me at once
straight away into the desert. We may be able to escape."

The Sheikh's camel glided silently away into the darkness, and the party
sat straining their sense of hearing to the utmost, making out plainly
e