"I am the daughter of Natas, and he has desired me to bid you welcome in his name, and I hope you will let me do so in my own as well. We are all dying to see this wonderful invention of yours. I suppose you are going to satisfy our feminine curiosity, are you not?" The daughter of Natas! This lovely girl, in the first sweet flush of her pure and innocent womanhood, the daughter of the unknown and mysterious being whose ill-omened name caused a shudder if it was only whispered in the homes of the rich and powerful; the name with which the death-sentences of the Terrorists were invariably signed, and which had come to be an infallible guarantee that they would be carried out to the letter. No death-warrants of the most powerful sovereigns of Europe were more certain harbingers of inevitable doom than were those which bore this dreaded name. Whether he were high or low, the man who received one of them made ready for his end. He knew not where or when the fatal blow would be struck. He only knew that the invisible hand of the Terror would strike him as surely in the uttermost ends of the earth as it would in the palace or the fortress. Never once had it missed its aim, and never once had the slightest clue been obtained to the identity of the hand that held the knife or pistol. Some such thoughts as these flashed one after another through Arnold's brain as he stood talking with Natasha. He saw at once why she had only that one name. It was enough, and it was not long before he learnt that it was the symbol of an authority in the Circle that admitted of no question. She was the envoy of him whose word was law, absolute and irrevocable, to every member of the Brotherhood; to disobey whom was death; and to obey whom had, so far at least, meant swift and invariable success, even where it seemed least to be hoped for. Of course, Natasha's almost girlish question about the air-ship was really a command, which would have been none the less binding had she only had her own beauty to enforce it. As she spoke the President and Colston--who had only lost himself for the time behind a mask and cloak--came up to Arnold and asked him if he was prepared to give an exhibition of the powers of his model, and to explain its working and construction to the Circle at once. He replied that everything was perfectly ready for the trial, and that he would set the model working for them in a few minutes. The President then told him that the exhibition should take place in another room, where there would be much more space than where they were, and bade him bring the box and follow him. A door was now opened in the wall of the room remote from that by which he and Colston had entered, and through this the whole party went down a short passage, and through another door at the end which opened into a very large apartment, which, from the fact of its being windowless, Arnold rightly judged to be underground, like the Council-chamber that they had just left.