“Master, I will not forget.”  Rrisa spoke dutifully, but his eyes were troubled.  His face showed lines of fear, of the struggle already developing in his soul.

“Go thou, then!  And remember that whatever happens, my judgment tells me it is best.  Raise not a hand of rebellion against me, Rrisa, to whom thou owest life itself.  To thy cabin—­go!”

“But, Master—­”

“Ru’c’h halla!”

The Arab salaamed and departed, with a strange look in his eyes.

When he was gone, the Master called Bohannan and Leclair, outlined the next coup in this strange campaign, and assigned crews to them for the implacable carrying-out of the plan determined on—­surely the most dare-devil, ruthless, and astonishing plan ever conceived by the brain of a civilized man.

Hardly had these preparations been made, when the sound of musketry-fire, below and ahead, drew their attention.  From the open ports of the cabin, peering far down, the three Legionaries witnessed an extraordinary sight—­a thing wholly incongruous in this hoar land of mystery and romance.

Skirting a line of low savage hills that ruggedly stretched from north to south, a gleaming line of metal threaded its way.  A train, southbound for Mecca, had halted on the famous Pilgrims’ Railway.  From its windows and doors, white-clad figures were violently gesticulating.  Others were leaping from the train, swarming all about the carriages.

An irregular fusillade, harmless as if from pop-guns, was being directed against the invading Eagle of the Sky.  A faint, far outcry of passionate voices drifted upward in the heat and shimmer of that Arabian afternoon.  The train seemed a veritable hornets’ nest into which a rock had been heaved.

“Faith, but that’s an odd sight,” laughed the major.  “Where else in all this world could you get a contrast like that—­the desert, a semibarbarous people, and a railroad?”

“Nowhere else,” put in Leclair.  “There is no other road like that, anywhere in existence.  The Damascus-Mecca line is unique; a Moslem line built by Moslems, for Moslems only Modern mechanism blent with ancient superstition and savage ferocity that implacably hold to the very roots of ancient things!”

“It is the Orient, Lieutenant,” added the Master.  “And in the Orient, who can say that any one thing is stranger than anything else?  To your stations, men!”

They took their leave.  The Master entered the pilot-house and assumed control.  As Nissr passed over the extraordinary Hejaz Railway, indifferent to the mob of frenzied, vituperating pilgrims, the chief peered far ahead for his first sight of Mecca, the Forbidden.

He had not long to wait.  On the horizon, the hills seemed suddenly to break away.  As the air-liner roared onward, a dim plain appeared, with here or there a green-blue blur of oasis and with a few faint white spots that the Master knew were pilgrims’ camping-places.