Arnold, as soon as he had exchanged greetings with the Princess, now known simply as Anna Ornovski, and his other friends and acquaintances in the colony, not, of course, forgetting Louis Holt, at once shut himself up in his laboratory by the turbine, and for the next four hours remained invisible, preparing a large supply of his motor gases, and pumping them into the exhausted cylinders of the _Ithuriel_, and all the others that were available, by means of his hydraulic machinery. Soon after four he had finished his task, and come out to take his part in a ceremony of a very different character to that at which he had been obliged to assist earlier in the day. This was the fulfilment of the promise which Radna Michaelis had made to Colston in the Council-chamber of the house on Clapham Common on the evening of his departure on the expedition which had so brilliantly proved the powers of the _Ariel_, and brought such confusion on the enemies of the Brotherhood. Almost the first words that Colston had said to Radna when he boarded the _Avondale_ were-- "Natasha is yonder, safe and sound, and you are mine at last!" And she had replied very quietly, yet with a thrill in her voice that told her lover how gladly she accepted her own condition-- "What you have fairly won is yours to take when you will have it. Besides, you cannot do justice on Kastovitch now, for it has already been done. We had news before we left England that he had been shot through the heart by the brother of a girl whom he treated worse than he treated me." But, as has been stated before, the laws of the Brotherhood did not permit of the marriage of any of its members without the direct sanction of Natas, and therefore it had been necessary to wait until now. As Radna and Colston were two of the most trusted and prominent members of the Inner Circle, it was fitting that their wedding should be honoured by the presence of the Master in person. An added solemnity was also given to it by the fact that, in all human probability, it was the first time since the world began that the mighty hills which looked down upon Aeria had witnessed the plighting of the troth of a man and a woman. Like all other formal acts of the Brotherhood, the ceremony was simple in the extreme; but, in this case at least, it was none the less impressive on that account. In a lovely glade, through which a crystal stream ran laughing on its way to the lake, Natas sat under the shade of a spreading tree-fern. In front of him was a small table covered with a white cloth, on which lay a roll of parchment and a copy of the Hebrew Scriptures. At this table, facing Natas, stood the betrothed pair with their witnesses, Natasha for Radna, and Arnold for Colston, or Alexis Mazanoff, to give him his true name, which must, of course, be used on such an occasion. In a wide semicircle some four yards off stood all the members of the little community, Louis Holt and his faithful servitor not excepted.