"I am neither. I am, however, a scientist, and I direct many other scientists. I am not mad. You have undoubtedly noticed several peculiar features of this place?" "Yes, particularly the artificial gravity, which has always been considered impossible, and those screens. An ordinary ether-wall is opaque in one direction, and doesn't bar matter--yours are transparent both ways and something more than impenetrable to matter. How do you do it?" "You could not understand them if I explained them to you, and they are merely two of our smaller developments. I have no serious designs upon the earth nor upon the Solar System, nor have I any desire to rule over, or to control the destinies of masses of futile and brainless men. I have, however, certain ends of my own in view. To accomplish my plans I require hundreds of millions in gold, other hundreds of millions in platinum and noble metal, and some five kilograms of the bromide of radium--all of which I shall take from the planets of this Solar System before I leave it. I shall take them in spite of the puerile efforts of the fleets of your Triplanetary League. "This structure, floating in a planetary orbit, was designed by me and built under my direction. It is protected from meteorites by certain forces of my devising. It is undetectable and invisible--your detectors do not touch it and light-waves are bent around it without loss or distortion. I am discussing these points at such length so that you may realize exactly your position. As I have intimated, you can be of assistance to me if you will." "Now just what could you offer any _man_ to make him join your outfit?" demanded Costigan, venomously. "Many things." Roger's cold tone betrayed no emotion, no recognition of Costigan's open and bitter contempt. "I have under me many men, bound to me by many ties. Needs, wants, longings and desires differ from man to man, and I can satisfy practically any of them. Personally, I take delight in the society of young and beautiful women, and many men have that same taste; but there are other urges which I have found quite efficient. Greed, thirst for fame, longing for power, and so on, including many qualities usually regarded as 'noble.' And what I promise, I deliver. I demand only loyalty to me, and that only in certain things and for a relatively short period. In all else, my men do as they please. In conclusion, I can use you two conveniently, but I do not need you. Therefore you may choose now between my service and--the alternative." "Exactly what is the alternative?" "We will not go into that. Suffice it to say that it has to do with a minor research, which is not progressing satisfactorily. It will result in your extinction, and perhaps I should mention that that extinction will not be particularly pleasant." "I say NO, you...." Bradley roared. He intended to give an unexpurgated classification, but was rudely interrupted. "Hold on a minute!" snapped Costigan. "How about Miss Marsden?"