_I would not have you fear from this foreword that my story may be some pedantic, heavily technical exposition. It is not; for it is fiction only--a romance with which to entertain you; an effort, by using fictional methods, to reduce theories purely imaginative into concrete form with as great a degree of plausibility as may be. It is this only I desire: to carry you with me as you read; to make plausible this flight of our imaginations momentarily set free from the tiny everyday universe which is all we have physically to envisage._ RAY CUMMINGS. _CHAPTER 1_ FREEDOM IN TIME AND SPACE I was busy with the Martian mail which had just arrived when the message from Brett Gryce reached me. I did not apprehend that there was anything of secrecy about it, since he was using the open air; yet there was in his voice a note of tenseness and his summons was urgent. "I can't come, Brett, until I get through the mail." I was rushed, and in a mood of ill-temper at the universe in general. "When will that be?" he demanded. "I don't know. It's accursedly large. Most of it seems to call for radio distribution--these Martians are always in a hurry." "Come when you can," he said quietly. "Tonight?" "Yes--tonight. No matter how late--I must see you, Frank." "I'll come," I said, and cut him off. It was long past trinight, with dawn beginning to brighten the sky beyond the masonry of lower Great-New York, when I had disposed of those miserable Martian dispatches. The Gryces lived in the Southern Pennsylvania area. My aerocar was at hand. I had rather planned to use it; but I was tired and in no mood for effort. I decided to take the pneumatic, since there was a branch--little traveled, it is true--which would drop me within some twenty kilometers of the Gryce home. They gave me an individual cylinder, with a bed if I cared to sleep. I did not. I lay there wondering what Brett could want of me; pleased also that I would see Francine--dear little Frannie. . . . Occasionally I would call the Director ahead. They are sometimes careless in the switching of special individual cylinders; and I had no wish to pass the branch and find myself bringing up at some gulf terminal with half the morning getting back. Once I called Brett. He would meet me with his aero at the end of the branch when I arrived. He, too, reminded the Director. A surly sort of fellow; the Gryces had already reported him to the General Traffic Staff of Great-London. I was not misdirected, however; but it was broad daylight when I emerged to find Brett impatiently awaiting me. And in a few minutes more we were landing at the aero-stage beside the Gryce home.