like this."

"Yes," said the professor; "they have us safely, and do not mean to let
us go."

"The young chief must have left word," said Frank bitterly, as he ground
his teeth.

"Of course, then, you give it up now?" said the professor quickly.

"No," said Frank firmly, "I am going to start--at once."

The lips of both his friends parted as if to utter a protest, but there
was something so determined in Frank's eyes, so stern and set about the
lines of his mouth, that they forbore, and the doctor spoke gently--

"Very well, Frank, lad," he said gravely; "you have had far more
experience among these people in the city than I have, and you know the
need of caution. Take care; a slip may mean destruction now we have
climbed so near the pinnacle of our hopes. I will say no more than
this--Go, and Heaven protect you."

"Yes," said the professor earnestly, and he held out his hand.

Frank grasped it firmly, and that of the doctor, who took his left, all
three standing silently for a few minutes.

Then Frank turned to go, but hesitated for a moment or two, for the
professor was running his eye over him critically.

"What is it?" said the younger man.

"I was looking to see if there is anything about you that might raise
suspicion."

"Well?"

"Nothing, my lad. I have had years of dealings with the people, and I
should never take you for anything but a native of the desert."

Frank nodded, and was mute again, as he walked out and across the path
to where his horse was waiting the beautiful animal whinnying softly in
token of recognition, and stretching out its velvety muzzle for the
caress that was always given and enjoyed. The next minute the rider was
in the saddle, with the Arab tossing its head and ambling gently beneath
him.

CHAPTER THIRTY SIX.

THE REACTION.

Out by the gate in the dazzling sunshine sat Ibrahim upon his tall
camel, the headgear for the present carefully arranged so as to make a
brave show, and the seven mounted guards waiting for the Hakim's learned
slave, who bore the reputation now of being deeply versed in magic to
such an extent that he could call down lightning from the skies and make
it do his will. A horror this to the ignorant Soudanese, and something
to make them tremble, but no exaggeration. For to us of this century
who can send our messages to the other side of the earth and receive
back answers in a few hours; talk with friends at a distance, and
recognise th