While the introductions were taking place, the wings of the air-ship began to vibrate and undulate with a wavy motion from forward aft, at first slowly, and then more and more swiftly, her propeller whirled round, and the wonderful craft rose without a jar or a tremor from the earth. Then the propellers began to revolve faster and faster, and she shot forward and upward over the trees amid the admiring murmurs of the crowds in the streets about the hotel. But little did those light-hearted sightseers dream, any more than did the captain and crew of the _Ithuriel_, that this aerial pleasure-cruise was destined to mark the beginning of a tragedy that would involve the whole of civilised humanity in a catastrophe so colossal that the like of it had never been seen or even dreamt of on earth before. From the wit of a woman and the weakness of a man were now to be evolved the elements of destruction that ere long should lay the world in ruins. CHAPTER VIII. THE NEW TERROR. FIVE years had passed since the _Ithuriel_ had vanished like a cloud from the sky, leaving, so far as the air-ship itself was concerned, no more trace than if she had soared into space beyond the sphere of the earth’s attraction and departed to another planet. All the rest of the winter of 2030-1, tidings had been sought most anxiously, but in vain, by the kindred and friends of those who had formed her crew during the ill-fated voyage on which she had disappeared into the unknown. The earth had been ransacked east and west, north and south, by the aerial fleet in search of the missing _Ithuriel_, but without result. She had been traced to St. Petersburg and Vorobièvŏ, but there, like the phantom craft of the Flying Dutchman, she had melted into thin air so far as any result of the search could show. But when the snows thawed on the mountains of Norway, and the bodies of eight Aerians who had formed her crew on her last fatal voyage were discovered by a couple of foresters in a melting snowdrift on the very spot on which Vladimir Romanoff had been killed with his companions by order of the Supreme Council, a thrill both of horror and excitement ran through the whole civilised world. That their death was intimately connected with the disappearance of the air-ship was instantly plain to everyone, and the only inference which could be drawn from such a conclusion was that at last some power, silent, mysterious, and intangible, had come into existence prepared to dispute the empire of the world with the Aerians, and, more than this, had already struck them a deadly blow which it was utterly beyond their power to return.