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 pinhead 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 engineroom 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.

With an odd persistence, though, the question continued to trouble my thoughts in the hours that followed, and when we finally swept in toward the solar system twelve hours later, it was with a certain abstractedness that I watched the slow largening of the yellow star that was our sun. Our velocity had slackened steadily as we approached that star, and we were moving at a bare one light-speed when we finally swept down toward its outermost, far-swinging planet, Neptune, the solar system's point of arrival and departure for all interstellar commerce. Even this speed we reduced still further as we sped past Neptune's single circling moon and down through the crowded shipping-lanes toward the surface of the planet itself.

Fifty miles above its surface all sight of the planet beneath was shut off by the thousands of great ships which hung in dense masses above it-that vast tangle of interstellar traffic which makes the great planet the terror of all inexperienced pilots. From horizon to horizon, it seemed, the ships crowded upon each other, drawn from every quarter of the Galaxy. Huge grain-boats from Betelgeuse, vast, palatial liners from Arcturus and Vega, ship-loads of radium ores from the worlds that circle giant Antares, long, swift mailboats from distant Deneb-all these and myriad others swirled and circled in one great mass above the planet, dropping down one by one as the official traffic-directors flashed from their own boats the brilliant signals which allowed a lucky one to descend. And through occasional rifts in the crowded mass of ships could be glimpsed the interplanetary traffic of the lower levels, a swarm of swift little boats which darted ceaselessly back and forth on their comparatively short journeys, ferrying crowds of passengers to Jupiter and Venus and Earth, seeming like little toy-boats beside the mighty bulks of the great interstellar ships above them.

As our own cruiser drove down toward the mass of traffic, though, it cleared away from before us instantly; for the symbol of the Federation on our bows was known from Canopus to Fomalhaut, and the cruisers of its fleet were respected by all the traffic of the Galaxy. Arrowing down through this suddenly opened lane we sped smoothly down toward the planet's surface, hovering for a moment above its perplexing maze of white buildings and green gardens, and then slanting down toward the mighty flat-roofed building which housed the Bureau of Astronomical Knowledge. As we sped down toward its roof I could not but contrast the warm, sunny green panorama beneath with the icy desert which the planet had been until two hundred thousand years before, when the scientists of the solar system had devised the great heat-transmitters which catch the sun's heat near its blazing surface and fling it out as high-frequency vibrations to the receiving-apparatus on Neptune, to be transformed back into the heat which warms this world. In a moment, though, we were landing gently upon the broad roof, upon which rested scores of other shining cruisers whose crews stood outside them watching our arrival.

Five minutes later I was whirling downward through the building's interior in one of the automatic little cone-elevators, out of which I stepped into a long white corridor. An attendant was awaiting me there, and I followed him down the corridor's length to a high black door at its end, which he threw open for me, closing it behind me as I stepped inside.

* * *