“Win.” Scobie raised a hand to stroke his chin, encountered his helmet, and sketched a grin at himself. “Sounds reasonable. But where did so much dust come from-and the ice, for that matter?”
“1 think-” Her voice dropped until he could barely hear, and her look went the way of Garcilaso’s. His remained upon her face, profiled against stars. “1 think this bears out your comet hypothesis, Colin. A comet struck Iapetus. It came from the direction it did because it got so near Saturn that it was forced to swing in a hairpin bend around the planet. It was enormous; the ice of it covered almost a hemisphere, in spite of much more being vaporized and lost. The dust is partly from it, partly generated by the impact.”
He clasped her armored shoulder. “Your theory, Jean. I was not the first to propose a comet, but you’re the first to corroborate with details.”
She didn’t appear to notice, except that she murmured further: “Dust can account for the erosion that made those lovely formations, too. It caused differential melting and sublimation on the surface, according to the patterns it happened to fall in and the mixes of ices it clung to, until it was washed away or encysted. The craters, these small ones and the major ones we’ve observed from above, they have a separate but similar origin. Meteorites-”
“Whoa, there,” he objected. “Any sizable meteorite would release enough energy to steam off most of the entire field.”
“1 know. Which shows the comet collision was recent, less than a thousand years ago, or we wouldn’t be seeing this miracle today. Nothing big has since happened to strike, yet. I’m thinking of little stones, cosmic sand, in prograde orbits around Saturn so that they hit with low relative speed. Most simply make dimples in the ice. Lying there, however, they collect solar heat because they’re dark, and re-radiate it to
melt away their surroundings, till they sink beneath. The concavities they leave reflect incident radiation from side to side, and thus continue to grow. The pothole effect. And again, because the different ices have different properties, you don’t get perfectly smooth craters, but those fantastic bowls we saw before we landed.”
“By God!” Scobie hugged her. “You’re a genius.”
Helmet against helmet, she smiled and said, “No. It’s obvious, once you’ve seen for yourself.” She was quiet for a bit while still they held each other. “Scientific intuition is a funny thing, I admit,” she went on at last. “Considering the problem, I was hardly aware of my logical mind. What I thought was the City of Ice, made with star stones out of that which a god called down from heaven-”
“Jesus Maria!” Garcilaso spun about to stare at them.
Scobie released the woman. “We’ll go after confirmation,” he said unsteadily. “To the large crater we spotted a few klicks inward. The surface appears quite safe to walk on.”
“I called that crater the Elf King’s Dance Hall,” Broberg mused, as if a dream were coming back to her.
“Have a care.” Garcilaso’s laugh rattled. “Heap big medicine yonder. The King is only an inheritor; it was giants who built these walls, for the gods.”
“Well, I’ve got to find a way in, don’t I?” Scobie responded.
“Indeed,” Alvarlan says. “I cannot guide you from this point. My spirit can only see through mortal eyes. I can but lend you my counsel, until we have neared the gates.”
“Are you sleepwalking in that fairy tale of yours?” Danzig yelled. “Come back before you get yourselves killed!”
“Will you dry up?” Scobie snarled. “It’s nothing but a style of talk we’ve got between us. If you can’t understand that, you’ve got less use of your brain than we do.”
“Listen, won’t you? I didn’t say you’re crazy. You don’t have delusions or anything like that. I do say you’ve steered your fantasies toward this kind of place, and now the reality
has reinforced them till you’re under a compulsion you don’t recognize. Would you go ahead so recklessly anywhere else in the universe? Think!”
“That does it. We’ll resume contact after you’ve had time to improve your manners.” Scobie snapped off his main radio switch. The circuits that stayed active served for close-by communication but had no power to reach an orbital relay. His companions did likewise.