he sound came from beyond a mass of rock, which projected from the
shelf over the edge of the precipice, the perpendicular rock seeming to
fall from here sheer to the torrent, that looked small and silvery now
from where they stood.

"It is a horse feeding," said Yussuf smiling. "They are over yonder."

The next minute they were by the projecting rock which cut the shelf in
two.

Yussuf went close to the edge, rested his hand upon the stone, and
peered over.

"Only a bird could get round there," he said, shaking his head, and
going to the slope above the ledge. "We must climb over."

Mr Burne looked up at the place where they were expected to climb with
a lugubrious expression of countenance; but he jumped up directly, quite
willing to make the attempt, and followed his companions.

The climb proved less difficult than it seemed, and on reaching the top,
some fifty feet above where they had previously stood, there below them
stood Ali Baba, cropping the tender shoots of a large bush, and as soon
as he caught sight of them he set up a loud neigh.

There was no sign of Lawrence, though, until they had descended to the
shelf on that side, when they found him lying upon the short growth fast
asleep, evidently tired out with waiting.

"My dear boy!" was on the professor's lips; and he was about to start
forward, but Yussuf caught him roughly by the shoulder, and held him
back.

"Hist! Look!" he whispered.

Both the professor and Mr Burne stood chilled to the heart, for they
could see the head of an ugly grey coarsely scaled viper raised above
its coil, and gazing at them threateningly, after having been evidently
alarmed by the noise which they had made.

The little serpent had settled itself upon the lad's bare throat, and a
reckless movement upon the part of the spectators, a hasty waking on the
sleeper's part might end in a venomous bite from the awakened beast.

"What shall we do, Yussuf?" whispered, the professor in a hoarse
whisper. "I dare not fire."

"Be silent, effendi, and leave it to me," was whispered back; and, while
the two Englishmen looked on with their hearts beating anxiously, the
Turk slowly advanced, taking the attention of the serpent more and more.

As he approached, the venomous little creature crept from the boy's neck
on to his chest, and there paused, waving its head to and fro, and
menacingly thrusting out its forked tongue.

The danger to be apprehended was a movement upon th