“We of Aeria are not accustomed to boast our prowess lightly, and I am threatening nothing that I cannot do. Still, I do not wish you to give the pledge I ask save in the fullest knowledge. If you will trust yourself with me on board the _Ithuriel_ for an hour under my pledge of your safe return I will prove to you to demonstration that your city would be as defenceless beneath our guns as a collection of tents would be. The moon is high enough now to give us plenty of light for the experiment if you think fit to make it.” The Sultan hesitated for a few moments, as though in doubt whether he would be permitted to return if he once allowed the _Ithuriel_ to carry him away from the earth. Then he remembered that no man had ever known the Aerian who had broken his word. He looked into Alan’s strong, frank face, and read there an absolute assurance that his safety would be respected. Then, with a slight inclination of his head, he said-- “Your words are wise. I will come, and if you convince me that you can do as you say I will swear by the holy name of the Prophet that I will make no war upon any man for a year from now.” Alan signalled to the _Ithuriel_, which ran in close to the terrace. The door of the deck-chamber opened, a gangway was run out, and for the first time in his life Sultan Khalid trod the deck of a cruiser of the air. The _Ithuriel_ and the _Vindaya_ at once mounted up into the now brightly moonlit atmosphere. The Sultan saw the myriad lights of his splendid capital sink swiftly down into a vast abyss that seemed to open beneath him. The dim horizon widened out until it enclosed an immense expanse of pale grey desert to the south, while to the north a dark stretch of sea spread out farther than the eye could reach. Up and up the air-ships soared until the lights of Alexandria glimmered like a faint white mist at the bottom of a seemingly unfathomable gulf. At length Alan, who was standing beside him, pointed down and said-- “There is your city. If I gave the word, a hundred shells a minute would be rained on to it from here. Do you think your guns could reach us?” “No,” said the Sultan, striving in vain to repress a shudder at the fearful prospect disclosed by Alan’s words. “But how could your shells strike that little patch of light which is miles away, and thousands of feet below us?” “That, too, I will prove to you, but not at the expense of your city.” He sent an order to the engine-room, and the _Ithuriel_ swerved round to the northward and, followed by the _Vindaya_, swept out over the Mediterranean, in the direction of Crete. Half an hour’s flight at full speed brought them in sight of a small rocky islet which showed like a black spot on the surface of the moonlit sea. The two air-ships were stopped six thousand feet above the water, and about four miles from the heap of rocks. Alan then gave orders for each of the ships to train four guns upon it.