While I mused thus at the window the two circling suns of Alpha Centauri had dropped behind us, and now, with a swift clicking of switches, the pilot beside me turned on our full speed. Within a few minutes our ship was hurtling on at almost a thousand light-speeds, flung forward by the power of our newly invented de-transforming generators, which could produce propulsion-vibrations of almost a thousand times the frequency of the light-vibrations. At this immense velocity, matched by few other craft in the Galaxy, we were leaping through millions of miles of space each second, yet the gleaming yellow star ahead seemed quite unchanged in size. Abruptly the door behind me clicked open to admit young Dal Nara, the ship's second-officer, descended from a long line of famous interstellar pilots, who grinned at me openly as she saluted. "Twelve more hours, sir, and we'll be there," she said. I smiled at her eagerness. "You'll not be sorry to get back to our little sun, will you?" I asked, and she shook her head. "Not I! It may be just a pin-head beside Canopus and the rest, but there's no place like it in the Galaxy. I'm wondering, though, what made them call us back to the fleet so suddenly." My own face clouded, at that. "I don't know," I said, slowly. "It's almost unprecedented for any star to call one of its ships back from the Federation fleet, but there must have been some reason----" "Well," she said cheerfully, turning toward the door, "it doesn't matter what the reason is, so long as it means a trip home. The crew is worse than I am--they're scrapping the generators down in the engine-room to get another light-speed out of them." I laughed as the door clicked shut behind her, but as I turned back to the window the question she had voiced rose again in my mind, and I gazed thoughtfully toward the yellow star ahead. For as I had told Dal Nara, it was a well-nigh unheard-of thing for any star to recall one of its cruisers from the great fleet of the Federation. Including as it did every peopled star in the Galaxy, the Federation relied entirely upon the fleet to police the interstellar spaces, and to that fleet each star contributed its quota of cruisers. Only a last extremity, I knew, would ever induce any star to recall one of its ships, yet the message flashed to our ship had ordered us to return to the solar system at full speed and report at the Bureau of Astronomical Knowledge, on Neptune. Whatever was behind the order, I thought, I would learn soon enough, for we were now speeding over the last lap of our homeward journey; so I strove to put the matter from my mind for the time being.