My voice trailed off. These were not Vic and Hope before me; they were unreal creatures, like the beings which had captured me. I could recognize the face and the figure of the woman I loved and of her brother; but they seemed to have no substance. Hope suddenly put her arms about me. She was sobbing. "Don't, Peter!" she whispered. "Don't look at me like that. I know how you feel. You--you and Vic--you aren't real to me, either! We're just shadows--lost souls...." "Buck up, Hope!" Vic's voice was kindly, yet firm and gravely commanding. "We're all right. Only--temporarily--we're Infra-Medians. Sit down, Pete, and let's talk. It may be that there's no time to lose in making some plans." * * * * * "First of all," I insisted, "tell me where we are; what's happened to us. Do you know?" "Where we are? Surely. Looking at it in one way, we're less than a mile from my laboratory." "But, Vic!" I protested. "Do you really mean that we're less than a mile from your laboratory; from our own world? If we were, we could see it; we'd bump into our own trees and houses and people; we'd be knocked down by automobiles, and--" "Two bodies cannot occupy the same space at the same time. Old law of simple physics. Is that what you mean?" interrupted Vic. "Why, yes." "And a body; what's that?" "A body? Why, matter, I suppose." "And matter is what?" "Anything that occupies space," I replied triumphantly. I had remembered that much from my physics classes. "True," smiled Vic. "But let's see. It is possible to have sound and light in the same place, isn't it? We can even add other things: heat and electricity, for example. Speaking of electricity, a tremendous current of it adds nothing to the weight of the wire carrying it, and nothing to its bulk, unless we have a heating overload. Current enough to kill a thousand men, or to do the work of a million horses, weighs nothing, is invisible, and actually does nothing until released in some form or other, either by accident or design." "True, but electricity isn't matter. Our old world is matter; I'm matter, and you're matter. Why don't we bump into things?" "Our old world is matter, true enough, but for the rest, you're wrong, Pete, old son. You're _not_ matter, any more. You're something else. In terms of our own being, you do not exist in your present form. This world does not exist. And the reverse is just as true." * * * * * I stared at him, bewildered. "What am I, then--a ghost?"