So air currents did not flow up from the spot where the star was directly above, since there were none. Or rather, it was the Knothole, where the Jet passed through. No Hadley cells, polar swirls, trade winds, or barren desert belts wrapping around the globe. Instead, here the effect of spin held sway.

He could see long streaming rivers of cloud begin above the ample dark blue seas, then arc over distances larger than the separation between the Earth and its moon, driven to higher latitudes of the immense Bowl. Purple anvils of sullen cumulonimbus towered up to seven kilometers above landscapes of mottled brown and red. The scale of all this violated his sense of what patterns could be possible. Clearly the whole vast contraption had been designed to hold everything constant—steady sunlight, no big differences of temperature to drive storms or trade winds. It left him with no intuitions at all of how weather got shaped.

Climate came from the spin, then. To pin its inhabitants to the ground, they spun it—and then got curious Coriolis effects.

Abruptly the name alone brought back his grad student days. That had been more than half a century ago, and there leaped to mind a drunken song of the climate modelers.

On a merry-go-round in the night

Coriolis was shaken with fright

Despite how he walked

’Twas like he was stalked

By some fiend always pushing him right!

Apparently Coriolis had been a mild man, but his force made hurricanes, tornadoes, jet streams, and assorted violences. Those should occur here—and as he thought it, he saw a brilliant white hurricane coming into view of the screen on his office wall. That slow churn of darkening clouds was the size of Earth itself, spinning its gravid whirl toward the shore of a huge sea. Trouble for somebody, he thought. Or some thing.

The knock on his door drew him back into the humdrum reality of SunSeeker.

Karl’s lean face was all smiles, which could be good news. There’s a first time for everything, Redwing thought. But the lean man folded himself into the guest chair and unloaded the bad news first.

“There’s a progressive crazing of those transparent ceramic windows we use for the astronomy,” he began. “Caused by mechanical stress or maybe some ions that get through the magnetic screen. Limits their working life.”

“You can fix it?”

He waved a hand lazily, somehow sure of himself. “Sure, got the printer making new ones right now. The external robos can slap them on when done, and I’ll feed the old ones in for materials stock. Not why I came to see you, Cap’n.” The slow smile again, above dancing eyes. “I’ve got an idea.”

“Good to hear,” Redwing said automatically. This was maybe the twentieth notion Karl had delivered this way. The man did deserve some credit, for he had spruced up the ship and made it run better. But the man was so focused on his machines that he was not much further use as a deck officer. Redwing could see Karl was settling in to bask in the tech details, and it was more efficient to just let him work through it.

“I’ve been tuning our scoop fields for the plasma we’re getting from that small star,” Karl said. “It’s not like protons incoming at a tenth of light speed, so I had to retune all the capture capacitors.”

Redwing knew the big breakthrough that made starflight possible, though it relied on tech you never saw from the bridge. The method of catching the sleet of protons, slowing them down between charged grids for electrical power, then funneling them into the fusion chambers where a catalyst worked the nuclear magic—it all happened in the halo around the ship, and then the burn occurred in its guts, where no one could ever go. We ride on miracles.

He nodded, waiting for the idea.

“So we’re flying with a scoop a thousand kilometers across now, all supported by nanotube mesh. Bigger funnel than we had before, ’cause the plasma’s weaker. I tuned it all up—had to use the full complement of our external in-flight robos, too.”

“I like the ride now,” Redwing allowed. “It doesn’t wake me up nights.”

Karl beamed. “Glad to hear it. Lowers the structural stresses, too. Then I thought—this scoop arrangement we’ve got isn’t optimal for where we are, so what would be better?”

Redwing wanted to ask him to just spit it out, but that didn’t work well with tech crew. “I’ll guess—the Jet?”

Karl’s face fell. “How did you know? If—”

“What else do we have in this system?” Redwing asked with a grin. “Had to be the Jet. Plus, you know we flew in here through that Jet. What a ride!”

Karl looked surprised at Redwing’s enthusiasm. The man was elaborately casual, but conservative to the bone. Useful in a deck officer, where a captain had to balance personality types against one another. A captain had to know when to take risks, not tech lieutenants.

Redwing had always thought that life’s journey wasn’t to get to your grave safely in a well-preserved body, but rather to tumble in, wrecked, shouting, What a ride! But he could see from Karl’s puzzled expression that the man thought captains should be sober-minded authority figures, steady and sure, without a wild side.

“Well, sir, yes—I looked into that. The scoop settings we had then weren’t as good at sailing up the Jet as the ones we have now, so…” Karl hesitated, as if his idea was too risky. “Why not use SunSeeker as a weapon?”

Now this was an idea. Not that he understood what it was, but the flavor of it quickened his pulse. “To…”

“Let me walk through it. Remember when we saw the mirror zone changing, painting a woman’s face on it? I was outside with robot teams to repair the funnel struts. I could see it direct, right out my faceplate. Incredible! It was Elisabeth, the one they captured with her team, mouthing words.”

Redwing gestured slightly to speed him up and Karl took the hint. “Even that—which lasted maybe an hour, then repeated every day or so—had an effect on the Jet. Gave it less sunlight, I guess, or just rippled the light over the Jet base. Big changes! A day or two later, I saw little snarls propagating out from the base of the Jet, at the star. They grew, too, moving out.”

“We all did.” It hadn’t seemed much different from the variations Redwing had seen, over time—knots in the string. He was still amazed the bright scratch across the sky was so stable.

Karl leaned forward, eyes excited. “The mirrors focus on that spot, delivering the heat to blow plasma off the star’s surface. Plus, there are stations circling the base of the Jet that must somehow generate magnetic fields. I’m guessing those big stations then shape and confine the Jet. So—” Karl cocked a jaunty grin. “—why not show them what we can do to the Jet?”

Redwing exhaled a skeptical breath. “To do what?”

“Screw it up!”

“So it—”

“Develops a kink instability. The disturbance grows as it advances out from the Jet base. It’s like a fire hose—you have to hold it straight or it snarls up and fights you like an angry snake.”

“Then when it gets to the Bowl…”

“I’m thinking we could force the kink amplitude to grow enough, it’ll snake out sideways. If it hits the atmosphere containment layer—that sheet that sits on top of the ring section—then it can burn clean through it.”

Redwing studied Karl’s eager face. This was world destruction on a scale Redwing had never imagined. Should he have?

“Then there’s the sausage instability—we get those sometimes in the funnel plasma, before it hits the capacitor sheets and slows down. A bulge starts in the flow, say, starting from turbulence. That bulge forces the magnetic fields out, and that can grow, too, just like the kink. You get a cylinder of fast plasma that looks like a snake that’s eaten eggs, spaced out along it.”