He had not been slated for revival on the passage at all, so his sensitivity to noise had not been an issue. And indeed, the shifting, grating clangor already irked him a bit. There was no way to damp it, so he would have to use noise-suppressing headphones. Certainly he would not have made the cut for active, awake crew.

The Wickramsinghs glanced at each other yet again, as if to say, Humor him—he’s a senior officer. Both inhaled deeply. Abduss said, “Please tolerate our unveiling this anomaly so that you may experience it as we did.”

“Um, yes.” He still felt irked, but ordered himself to behave as an officer should.

Mayra said, “Notice that the luminous gas, as you put it, is very straight.”

Cliff zoomed the image—and blinked. He had expected a ragged cloud of expelled debris, the star’s outer layers blown off. The plume seemed to point at the star ahead. “Pretty, at least. Why so sharp?”

Abduss said carefully, “We wondered, too. None of the astronomical analysis systems had an explanation. But it did alert us to the infrared spectrum.”

“Of this plume? Why—?”

Mayra switched to the middle infrared bands, and his mouth fell open. An orange circle stretched across the sky. The plume was an arrow stuck in the exact center of some target.

“The plasma apparently comes from the center of that massive infrared region. It is mostly of hydrogen, and its ions eventually find electrons and they unite,” Abduss said, as if he were talking to a student. “That is the hydrogen line we see, the plume cooling off.”

Mayra added, “But it did lead our attention to the huge region of soft infrared emission.”

“Hey, I’m a biologist—”

“We awoke you because the infrared signature is clear. The circle we see is solid, not a gas.”

His irritation vanished. Even a biologist knew enough to be startled by the implication. All he could manage to say was, “That’s impossible.”

Mayra said mildly, “When I first saw it, I, too, assumed it to be gas. The spectral lines prove otherwise.”

He studied it, trying to allow for perspective. “A disk?… It’s huge.”

“Indeed,” Mayra said.

“But it can’t be a planet. It would be bigger than any star.”

Abduss nodded. “We are approaching from behind it, and at present speed will come directly alongside within weeks. The … thing … is about three hundred AU away from us.” He smiled quickly, as if embarrassed. “Allowing for that, look closer.”

“This is why we awakened you,” Mayra said.

He blinked. “It’s … artificial?”

“Apparently,” Mayra said.

“What? How—?”

“We have just come into view of this object, by coming alongside. It drew our attention because its star suddenly appeared—presto! We could not see it before because the … the cap, whatever it is … blocked the starlight as we overtook it.”

Abduss added helpfully, “Infrared study shows that it is not a disk. It’s rounded. We witness it from behind, with the plasma plume coming through a hole at the exact rear center. The cap radiates at the temperature of lukewarm water.”

“A … sphere?” He saw it then, the image snapping into perspective. He was looking at a ball with a hole in its bottom. Through that hole, the star glowed. His imagination scrambled after an old idea. “Maybe it’s a, what was the name—?”

“A Dyson sphere,” Mayra provided. “We thought so at first, too.”

“So this is a shell?”

She nodded. “A hemisphere, perhaps—a sphere halfway under construction. Perhaps. Only—the old texts reveal quite clearly that Dyson did not dream of a rigid sphere at all. Rather, he imagined a spherical zone filled with orbiting habitats, enough of them to capture all of the radiant energy of a star.”

Abduss thumbed up a reference to these ideas on a side screen. Good—they had done the homework before awakening him. But if not a Dyson sphere, what—?

Mayra said, “We have watched and run the Doppler programs carefully. The hemispherical cap is spinning about the same axis formed by the plume.”

Abduss said helpfully, “Only by rotating such a shell could one support it against the star’s gravity.”

“Like this ship.” He nodded, trying to guess Abduss’s point. “Centrifugal gravity. But a complete, rigid sphere … spinning … that would be impossible, right? Gravity would pull it in at the poles.”

They both nodded. Abduss said, “Still, the configuration is not stable.”

They both looked at him, so he went on, thinking aloud. “The shell should fall into the star—it’s not orbiting. There’s some sort of force balance at play here. Odd construction, indeed. Just spinning isn’t enough, either—the stresses would vary with curvature. You’d need internal supports.”

Mayra said, “Quite right, I believe. My first degree was in astrophysics and I have some ideas about this object, but—” She bowed her head and shrugged.

As matters developed, there was a great deal behind Mayra’s modesty. In the next day, eating five meals to build himself up, he learned as much about the Wickramsinghs’ subtleties as he did of the strange object they had discovered. They were deferential toward him, unveiling their ideas slowly, allowing him to come to his own conclusions. This helped greatly as the magnitude of implication grew.

He didn’t even ask about Scorpii 3 until hours later, when Abduss and Mayra were using the control room facilities to lecture him. The planet, their destined home, was a long way off still, and deserved the nickname Glory. Scorpii 3 was the second nearest habitable-seeming world ever found, after the Alpha Centauri base. A fast-burn probe had verified the bio-signatures found by deep space telescopes two generations before SunSeeker’s launch. A wonder, with strong ozone lines, a lot of water, and tantalizing hints of green chlorophyll in the spectrum. A dream world. No sign of any artificial electromagnetic emissions, after big dishes had cupped their ears toward it for decades. Plus the mysterious grav waves that made no sense, considering that there were no big masses in the system to send out such quadrupole emissions.

He looked at it in the high amplification forward scope, but it was just a flickering blur through their bow shock. Scorpii 3 was barely visible because it hung near the edge of the structure ahead, though it was many light-years away. He looked at the screens, trying to get his head around what that vast bulk could mean. But emotion overwhelmed him. Pure wonder.

Unimaginable, yes. Bigger than the orbit of Mercury, huge beyond comprehension, the hemisphere was an artifact, a built thing, the first evidence of another intelligence in the galaxy. Not a trickle of radio waves, but a giant … riddle.

He took a long breath, relaxed into the observer’s chair and headpiece, and let the slow, long wavelength rumble of the starship run through his bones. And thought.

The Wickramsinghs felt it was a matter of biology. Wake the biologist!

Cliff wrinkled his nose. He had been irked, sure, but the Wickramsinghs were right: You see trouble, you call for help. But he wasn’t prepared for this. But as well he saw that none of that now mattered.

Science had speculated about intelligence for centuries, as probes spread out through a desert of dead worlds. The Big Eye telescopes in the twenty-first century had found warm, rocky worlds resembling Earth, and some had the ozone spectral lines that promised oxygen atmospheres. There the promise had ended. Here and there flourished slime molds in deep caverns, or simple ocean life, maybe—cellular colonies still unable to shape themselves into complex forms, as Earth’s life had more than a billion years ago. Sure, there was life, the consensus said … boring life.

To find an artifact of such immensity … it made his mind reel.

Then Abduss said, almost casually, “There is something more. Why we realized the protocols demanded that you be awakened. We have detected narrow-band microwave traffic from near the star.”