"We're back to them assuming they'd be coming back when they left," Hafner agreed. Something was gnawing at the back of his brain, something about that huge artifact that seemed wrong. But he couldn't place it. "I gather the boat's heading for a passage through the sphere. Colonel, you mentioned last night you brought a telescope along?"
"A small one, yes." Meredith turned away from the viewport. "Perez, give me a hand and we'll set it up in here."
The two men left, and Carmen and Loretta resumed their examination of the boat's manual. Easing into the seat beside Carmen, Hafner stretched out his leg and tried to nail down what was bothering him.
He hadn't succeeded by the time Meredith and Perez had the telescope set up between the two control panel seats … but an hour later, as Carmen was calling attention to a curious flattening of the sphere's limb, he got at least a piece of it.
"Best guess is that the sphere wasn't finished and that we're coming up on the uncompleted edge," Meredith was suggesting as Hafner limped over from the side viewport to the group huddled by the telescope.
"Seems silly to start a project that size and then not finish it," Carmen said.
"Their Congress must've cut the funding," Meredith said dryly, eliciting a snort from Perez.
"Or maybe they discovered it wasn't working," Hafner offered. "A superconductor like cable material would be great for collecting light and particle energies, but I'm not at all sure how you'd then turn the heat into something useful."
"What's wrong with thermocouples?" Perez asked.
"You need a temperature difference somewhere for those to work," Meredith said.
"As a matter of fact, it seems to me that almost all energy-extraction schemes require an energy differential."
"Maybe they know a method that doesn't," Loretta suggested. "After all, they built at least half the sphere before they quit."
"The Poms told me the radiation spectrum from cable material lacks some lines,"
Carmen said doubtfully. "Could something like that be the 'cool' part of the extraction cycle?"
Meredith shrugged. "That's as good a guess as any. Maybe we'll know better when we get a look at the inner surface."
"There's something else, though," Hafner muttered. "Something else that's not right … "
"Well, when you think of it, let us know," Meredith said,peering through the telescope. "Carmen, is there anything like an emergency beacon aboard that we ought to trigger?"
"It's already on," Loretta told him, pointing to one of the indicators. "I believe it's been going since we got here."
"And no response. Doesn't look very promising."
He spent the rest of the day struggling to hide his feelings from the others.
Fortunately, everyone was so busy discussing and observing the sphere that they didn't seem to notice his silence. When, during dinner, Carmen did, he passed it off as temporary discomfort in his leg. She didn't press the point then; but when they all returned to the passenger cabin that evening she casually took the bed next to his, and a few minutes after Meredith turned down the lights he sensed her lean over the narrow gap separating them.
"You all right, Peter?" she whispered. "You're quieter than I've ever seen you."
In the darkness he shook his head. "There's nothing you can do," he whispered back. "If I'm right … and we'll know in a day or two."
"Want to talk about it?"
"No. Not until I know for sure."
She didn't say any more, but a moment later her hand reached across to touch his.
He gripped it tightly … and, eventually, tell asleep.
By morning the sphere filled nearly half the sky, giving a bright red glow to everything within range of a viewport and triggering a low hum that Carmen finally identified as the boat's cooling system. The light was too intense for telescopic viewing to be safe, but Perez discovered that by using a piece of cardboard with a small piece cut out, enough of the glare could be eliminated to see the holes through which glimpses of the true sun had earlier been visible. In all he located twenty-eight gaps of various sizes, their positioning on the surface following no pattern anyone could detect. For a while there was a lively discussion of their possible function, but it eventually died from lack of data.
Hafner stayed out of the discussion; for him, the gaps merely added to his gloom.
And two hours after lunch the lifeboat rounded the ragged edge and entered the sphere.
"You know," Carmen said, shaking her head slowly, "I don't think I really believed Peter was right … until now."
There were murmurs of agreement; and even Hafner found his depression lifted temporarily by the sheer grandeur of the sight. This side glowed, too, but its intensity was considerably muted, as if the Spinners had coated their superconducting material with something to send the light outward. Attached to the sphere they could see clumps of rock spaced at regular intervals in all directions; on the very closest the telescope was just able to pick out spiderwebthin lines leading outward like latitude-longitude markings on a globe.
"Asteroids," Meredith identified the rocks, shading his eyes as he peered farther away down the vast curved surface. "Held in place by a framework of Spinneret cable. So that's why they needed something that strong—they've got to support umpteen tons of rock against the sphere's rotation."
"Ideal for the job, too," Perez murmured. "Flexible enough that you don't need to smooth out the asteroid much to make good contact."
"What are they for?" Loretta breathed. "The asteroids, I mean."
"Customs ports, maybe," Perez suggested. "Those holes must have been how ships were going to get in and out when the sphere was finished."
"More likely they were where the antigrav stabilizers were located," Hafner spoke up. "Even rotating, the sphere's position isn't really stable; they'd need some way to make periodic corrections." He hesitated. "And they must also be where the sphere's heaters are set up."
They all turned to face him. "The what!" Perez asked.
Hafner took a deep breath. "We were wrong about the sphere's purpose. Even if it collected and radiated every bit of the interior sun's light, it couldn't possibly get any hotter than about three hundred degrees absolute—room temperature, essentially. But in fact it's at least ten times that hot. There's no way that could happen without a massive input of energy."
"That's ridiculous," Perez snorted. "You must have made some order-ofmagnitude error."
Hafner shook his head. "I almost wish I had. But it's a perfectly straightforward Stefan-Boltzmann calculation."
"All right, then, let's assume you're right," Meredith said. "Can you give a reason why they'd go to that kind of trouble?"
"It wasn't just to heat their planet up," Hafner said. It was odd, a small observer in his brain noted, how even now he avoided simply coming out and saying it.
"Orbiting reflectors could have done that. A smaller sphere would have done if they'd decided they wanted a red sky. It wasn't built to live on; they wouldn't have needed to heat it like that and I suspect we'll find the main shell is too thin to support much weight." He paused. "Colonel Meredith … what would you do if you knew there was an enemy looking for your position and you didn't have the strength to fight him?"
Meredith's eyes gazed unblinkingly into his. He's figured it out. Hafner thought. I was right, then: it does make sense. God help them … and us. "I would retreat," the colonel said quietly. "Or else try and camouflage myself. Is that it?"
"No," Carmen whispered. "You don't mean—they built the sphere to make themselves look like a red giant star system?" Hafner nodded. "It fits, doesn't it?