fading and the first gleams of dawn were breaking through the eastern
mists. At such a time the appearance of the vast desert was especially
gloomy and depressing.

Thyra turned her gaze in the direction of the town.

What cloud was that coming thence, and advancing along the plain
towards the camp?

The Greek girl strained her eyes to penetrate the mist; in this she was
assisted by the growing light of the morn.

Presently the cloud shaped itself into recognisable distinctness.

It was a mass of armed men.

The Turks were marching on their track!

Thyra's terror for a moment kept her spellbound.

This onset boded destruction to herself and all her friends; above all,
to him she loved best.

Involuntarily she uttered a cry of alarm, which at once aroused the
whole of the camp.

The Arabs sprang to their feet, and seized their arms.

In an instant all was commotion.

Kara-al-Zariel heard that beloved voice, and in an instant was at
Thyra's side.

"What has alarmed the Pearl of the Isles?" he asked, in the poetic
phraseology of his race.

Thyra stood with dishevelled hair, and dilated eyes fixed upon the
approaching army, at which she pointed with trembling fingers.

"Look! look!" she exclaimed, "they are coming--the Turks are upon us!"

Kara-al-Zariel followed her gaze.

He saw the cloud; he knew the danger.

"To horse!" he thundered. "To arms! every son of the desert, and every
Christian guest!"

Instantly the horses were untethered, and the riders mounted; armed men
assembled on foot, and every warrior appeared in readiness.

Jack Harkaway and his friend Harry, by this time familiar as old
soldiers with these sudden calls to arms, soon answered the summons;
and the rest of their party, on hearing the danger, were not backward
in preparing for it.

There were in the encampment a large number of fleet Arab steeds, more
than were actually required by the tribe, but the chief, like many of
his race, dealt largely in horseflesh.

This was particularly fortunate on the present occasion, for their
Christian allies could also be mounted, and if overwhelmingly
outnumbered by the enemy, could save themselves by flight.

All the more experienced warriors were now sent to the front, to face
the first shock of the coming attack.

Kara-al-Zariel led a beautiful steed to Thyra.

"Mount, sweet maiden," he said; "This steed is one of fleetest. Go,
ride on towards the sea, for our enemies are coming fa