Hence it is that all of a sudden Sir Lionel finds himself in the midst of half a dozen Arab riders, who bar farther progress.

It is the unexpected that happens.

He attempts the same system of tactics that were so successful in the previous difficulty, but they do not pass current with these fierce men.

Immediately the two Franks are set upon by the desert tigers.  Two seize Sir Lionel and drag him from his steed, he resisting desperately.  What a great pity he exhausted his resources so thoroughly in the first round.  Ten men could not overcome him then, while two manage to hold him quiet now.

Philander, emboldened by his former success, thinks he can show them a trick or two that will count; but a blow chances to fall upon his bony steed’s haunches, starting the animal off, and the professor, throwing valor to the four winds, proceeds to clasp his arms tightly around the horse’s neck, shouting out an entreaty for some one, in the name of Julius Cesar, Mohammed, or Tom Jones, to stop the wicked beast before he makes mince-meat of his master.

One of the desert raiders gallops alongside, and, clutching the bridle, turns the runaway around.

By this time the commotion above has increased, and it even sounds as though the men of Bab Azoun might be starting out in quest of the fugitives who have given them the slip.

What are these sounds closer by—­the thunder of many hoofs, the wild neighing of steeds?  It is as though a squad of French cavalry might be rushing down upon them.

The leader of the small Arab force gives quick orders, and his men immediately fall into line of battle, ready to meet the foe, if perchance such proves to be the character of the cavalcade.

Now they burst out of the aloe thicket—­they come dashing straight on toward the spot where the little company is gathered.

The moonlight falls upon them.  Most of the horses are seen to be riderless, yet they are the pet steeds of the outlaws, animals upon the backs of which they have committed depredations on the desert, and laughed pursuit to scorn.

Upon two of the foremost chargers human figures may be seen, and one glance tells them who these worthies are.

Lady Ruth is the first to exclaim: 

“Why, it is John Craig.”

“He will be killed, see these fellows getting ready to fire.  John, take care!” and Aunt Gwen, in her eager desire to warn the doctor, waves her hands in the air, one of them grasping a fluttering white kerchief.

They hear the cry, they see the signal, and their eyes take in the line of dusky warriors that awaits their coming.

“Down, monsieur!” exclaims Mustapha.

Not a second too soon do they drop upon the necks of their horses, for a blinding flash comes from the men of Bab Azoun, a flash that is accompanied by a roar, and a hail-storm of lead sweeps through the space occupied by the forms of John Craig and his guide just a brief interval before.