I nodded and listed the causes, to hold off the idea of a personally evil cosmos. “Long nights, weird seasons, shortage of several trace elements, ultraviolet poverty coupled with X-ray and particle irradiation, gravity tending to throw terrene fluid balances out of kilter, even the geological instability. Some of their best mines collapsed in earthquakes in the early days, did you know?—and never could be reopened. Oh, yes, it’s a hard world for humans.”

My fist struck the control panel and I said with a barren anger: “But so are others. There’s nothing wrong here that men haven’t found, and beaten. The wildlife is worse on Zion, the weight is heavier on Atlas, a full-fledged ice age is under way on Asgard, Lucifer is hotter and has a higher particle count—”

She turned in her seat to face me. Sundown light, streaming through the turret, changed her gold hair to copper against purple shadows. “But none of those were attacked,” she said.

“Not yet,” I said. “At least, as far as we know.”

We should not have mentioned it. The thought had haunted us since we returned from our last voyage and got the news. It dwelt in the back of every mind on Earth. Perhaps it had done so since man first ventured beyond the Solar System. Our few score parsecs of exploring are no trail whatsoever into that wilderness which is the galaxy. Who can doubt that others prowl it, with longer legs and sharper fangs?

Why had they struck? How? Where else? Who’s next?

The Sibyllans did their best to answer Laurie’s questions and mine. But not only were they hard-pressed for time and dull-witted with exhaustion, their information was scant. I had now inspected the ruins, some photographs of ships in flight, eyewitness accounts, compiled histories. The basic narrative was in my brain.

The raiders could not hit everywhere at once. Josiah Brenner, Tom’s father, President in his day, got most population centers evacuated before they went up in fireballs. A majority already lived on isolated farms, it took so many hectares to support one person. For the same reason, the former townsfolk scattered across the whole habitable planet afterward.

The result was that hardly anyone today knew anything that I did not. In fact, my picture of the catastrophe was clearer than most. The ordinary Sibyllan had neither time nor energy for studying the past. The educational level had plummeted; children generally left school to work before they were twelve Earth-years old. Folklore took the place of books.

The books themselves were vague. No real census or scholarship was possible. “Casualties were heavy,” said the chroniclers, and told many tales of suffering and heroism. But the figures they gave were obvious guesswork, often contradicting someone else’s. I believed I could make a better estimate myself on the basis of one fact. The Sibyllan population which the original colonizing scheme had projected for this decade was some two hundred thousand. The actual population was a twentieth of that.