When he had gone I plunged at once into the task of learning the control and operation of our craft. The next two hours I spent under the tutelage of Sarto Sen, and at the end of that time I had already learned the essential features of the ship's control. There was a throttle which regulated the frequency of the vibrations generated in the engine-room below, thus increasing or decreasing our speed at will, and a lever and dial which were used to project the propelling vibrations out at any angle behind us, thus controlling the direction in which we moved. The main requisite in handling the craft, I found, was a precise and steady hand on the two controls, since a mere touch on one would change our speed with lightning swiftness, while a slight movement of the other would send us millions of miles out of our course almost instantly.
At the end of two hours, however, I had attained sufficient skill to be able to hold the cruiser to her course without any large deviations or changes of speed, and Sarto Sen had confidence enough in my ability to leave me alone at the controls. He departed down the little stair behind me, to give a few minutes' inspection to the generators below, and I was left alone in the conning-tower.
Standing there in the dark little room, its only sound the deep humming of the generators below and its only lights the hooded glows which illuminated the dials and switches before me, I gazed intently through the broad fore-window, into that crowding confusion of swarming suns that lay around us, that medley of jeweled fires in which the great star Alto burned like a living flame. For a long time I gazed toward the star that was our goal, and then my thoughts were broken into by the sound of Sarto Sen reascending the stair behind me. I half turned to greet him, then turned swiftly back to the window, stiffening into sudden attention.
My eyes had caught sight of a small patch of deep blackness far ahead, an area of utter darkness which was swiftly expanding, growing, until in less than a second, it seemed, it had blotted out half the thronging stars ahead. For a moment the sudden appearance of it dumfounded me so that I stood motionless, and then my hands leaped out to the controls. I heard Sarto Sen cry out, behind me, and had a glimpse of the darkness ahead, obscuring almost all the heavens. The next moment, before my hands had more than closed upon the levers, all light in the conning-tower vanished in an instant, and we were plunged into the most utter darkness which I have ever experienced. At the same moment the familiar hum of the vibration-generators broke off suddenly.
I think that the moment that followed was the one in which I came first to know the meaning of terror. Every spark of light had vanished, and the silencing of the vibration-generators could only mean that our ship was drifting blindly through this smothering blackness. From the cruiser's hull, below, came shouts of fear and horror, and I heard Sarto Sen feeling his way to my side and fumbling with the controls. Then, with startling abruptness, the lights flashed on again in the conning-tower and through the windows there burst again the brilliance of the starry heavens. At the same moment the vibration-generators began again to give off their deep humming drone.
Sarto Sen turned to me, his face white as my own. Instinctively we turned toward the conning-tower's rear-window, and there, behind us, lay that stupendous area of blackness from which we had just emerged. A vast, irregular area of utter darkness, it was decreasing rapidly in size as we sped on away from it. In a moment it had shrunk to the spot it had been when first I glimpsed it, and then it had vanished entirely. And again we were racing on through the familiar, star-shot skies.
I found my voice at last. "In the name of the Power," I exclaimed, "what was that?"
Sarto Sen shook his head, musingly. "An area without light," he said, half to himself; "and our generators—they, too, could not function there. It must have been a hole, an empty space, in the ether itself."
I could only stare at him in amazement. "A hole in the ether?" I repeated.
He nodded quickly. "You saw what happened? Light is a vibration of the ether, and light was non-existent in that area. Even our generators ceased to give off etheric vibrations, there being no ether for them to function in. It's always been thought that the ether pervaded all space, but apparently even it has its holes, its cavities, which accounts for those dark, lightless areas in the heavens which have always puzzled astronomers. If our tremendous speed and momentum hadn't brought us through this one, the pull of the different stars would have slowed us down and stopped us, prisoning us in that dark area until the end of time."