“Now,” he said to the Sultan, “fix your glass on that mass of rocks down yonder and watch what happens.” As he spoke he raised his hand and the eight guns were discharged simultaneously. The Sultan heard no report and saw no flash, but a few seconds later he saw through the night glasses that Alan had given him a vast mass of flame of dazzling brilliancy burst out over the islet, covering it completely, for the moment, with a mist of fire. “Now you shall see the effects of our shells,” said Alan. The two vessels sank rapidly down in a slanting direction towards the spot where the projectiles had struck. A hundred feet from the surface of the water they stopped, and Alan said-- “Now look for the island.” Khalid swept the sea with his glass. The islet had vanished, the waves were breaking over what seemed to be a sunken reef, and that was all. With hands that trembled, in spite of all that he could do to keep them steady, he took the glass from his eyes, saying in a voice that was shaken by irresistible emotion-- “God is great, and I am but a man, while you are as demigods. It is enough! I will give the pledge you ask for.” CHAPTER XVII. AN UNHOLY ALLIANCE. WITHIN a couple of hours after the destruction of the islet Sultan Khalid was back in his palace, and the _Ithuriel_ and the _Vindaya_ had departed with their prisoners of war for Kerguelen. Alan, quite content with the advantage he had gained by obtaining the Sultan’s pledge of peace for a year, in comparison with which even the capture of one of the Russian air-ships was of trifling importance, had determined not to run the needless risk of an encounter with Olga’s fleet, for he had learnt the strength of it from Lossenski, and saw that it would be madness to attack it. Added to this there was far more important work in hand for him to do, for it was absolutely imperative that a full report of what he had discovered with regard to the proposed alliance between Olga and the Sultan should be laid before the Council with as little delay as possible, for if it ever became an accomplished fact it could not fail to enormously complicate the coming struggle for the mastery of the world. Therefore, as soon as he had placed a prize crew on board the _Vindaya_, under the command of Alexis, he gave orders for the two air-ships to proceed southward at full speed, having bidden the Sultan farewell on the terrace of his palace, and left him to draw what moral he could from the brief but startling experience that the midnight hours had brought him. A few minutes before twelve on the following night the inhabitants of Alexandria were thrown into a state of the most intense excitement by a marvellous appearance in the southern heavens. Long streams of light, which in power and brilliancy excelled even the great electric suns with which the city was lighted, shot down out of the skies, flashing hither and thither, and sweeping the earth below it in vast curves of radiance.