Hardly had the Sultan finished the perusal of this strangely curt and yet all-pregnant letter when a cry from Lossenski’s two attendants caused him to look up. If what he had seen but a few minutes before had amazed him, what he saw now fairly stupefied him. A second air-ship, similar in size and shape to the first, but with a hull of a strangely lustrous blue metal, had dropped without sign or sound out of space, and was hovering exactly above Lossenski’s vessel with her ten long slender guns pointing in all directions. A moment later she seemed to drop bodily on to the Russian air-ship, splintering her thin steel masts with the weight of her hull, and yet stopping in her descent before she crushed in the glass dome of the deck. The next instant a score of men slipped swiftly over the side and gained the open door of the Russians’ deck-chamber. Then there came a sound of fierce cries and oaths, and the quick crackling reports of repeating pistols. The envoy’s two companions turned as though to fly, but two shots fired in quick succession brought them down before they had made a couple of strides. Then a dozen men leapt down upon the terrace and covered Lossenski and the Sultan with their pistols before they had time to recover from the stupefaction into which the suddenness of the attack had thrown them. The next moment a man, whose splendid stature raised him a good head above the Russian and the Moslem, came down the steps from the deck of the now captured air-ship. As he advanced towards them Khalid, brave and haughty as he was, looked up at him almost as he might have looked upon the visible shape of one of the angels of his faith. He was dressed in the Aeria costume, save for the fact that, instead of azurine and gold, his winged coronet was black and lustrous as polished jet. In his left hand he carried a magazine pistol, and in his right a long slender rapier with a blade of azurine that gleamed with an intense blue radiance in the light of the electric lamps. “Orloff Lossenski, you are our prisoner! Go back to your ship or you will be shot where you stand. Sultan Khalid, have you received that letter in your hand from this man?” Alan’s words came quick and stern, but before they were spoken the Sultan had put a golden whistle to his lips and blown a shrill call, in instant obedience to which a stream of armed guards issued from a door of the palace opening on to the terrace, spread out into a semi-circle, and in turn Alan and his companions were covered by a hundred rifles. “Now, sir, whoever you are,” exclaimed the Sultan, recovering at once his courage and his composure, “you are _my_ prisoner! Throw down your arms, or”-- “Stop!” cried Alan, in a voice that rang clearly over the whole terrace. “Don’t you see that your palace is under our guns? Fire a shot, and in an hour it shall be a heap of ruins.”