Stephen Baxter - Starfall

But this was an extraordinary moment which required extraordinary measures, as the Empress Shira had patiently explained to Folyon himself—and as he himself had had to relay to a reluctant Lieserl, deep in the belly of the sun. This was total war. Even Thoth had been infected by the smart plague. Every resource available to the empire had to be dedicated to the fight—and that included even Thoth and its ancient community. So Thoth's orbit had been carefully lifted from equatorial to a higher-inclination plane where the habitat was expected to lie in the path of the invasion fleet; and so the wormhole had, for now, been shut down.

The sunchildren had fulfilled their duties to the letter. But Folyon, conditioned since childhood to dedicate his life to a single goal, had found it hard to accept this distortion of his deepest imperatives.

Not wishing to exacerbate the crew's difficulty with his own qualms, he left the bridge and made for the observation deck. As so often, he dealt with his troubles by immersing them in the healing light of the sun, giver of life.

The sun was a flat, semi-infinite landscape, encrusted by granules each large enough to swallow the Earth, and with the chromosphere—the thousand-kilometre-thick outer atmosphere—a thin haze above it all. The sunscape crawled beneath the habitat slowly, but that slowness was an artefact of scale, a collision of human senses with the sheer bulk of the sun. In this free orbit around the sun Thoth was actually travelling at five hundred kilometres a second. Folyon knew how privileged he was to spend his life in the orbit of the mighty star, the physical and philosophical core of human culture. At the prayer hours he would look away from the sun's processed light to the distant stars, and he imagined every human eye, even across interstellar distances, turned to the sun, towards him.

And he wondered how many of those observers even knew of the habitat's existence, or its purpose.

Deep below the habitat, tracking its orbit, the tetrahedral Interface of a wormhole, linked to the mouth tended by Thoth, was suspended in the body of the sun. Searing-hot gas poured into its four triangular faces, so that the Interface was surrounded by a sculpture of inflowing gas, a flower carved dynamically from the sun's flesh. In normal times this solar material would spew from the wormhole mouth cradled by Thoth, to dissipate harmlessly. Thus the wormhole was nothing less than a crude refrigeration mechanism, by which solar heat was pumped away from the fragile human-built construct that housed the soul of Lieserl, and enabled her to survive in the sun's fire. And it was all for a higher goal. Lieserl was a monitor, sent into the sun to investigate a complex, dark-matter canker that seemed to be building up at the star's heart.

Thoth's purpose outdated even the ancient empire of the Shiras, but, designated as a temple to Sol, it had always been maintained faithfully by the Empresses' lieutenants. Now Lieserl's wormhole was to be used as a weapon of war—but even this remarkable incident, Folyon knew, was but an episode in the greater history of Thoth and Lieserl.

A sunchild touched his arm, a young woman. His thoughts, as so often, had drifted away from the here and now. Sunchild Mura said, "The time is close, sun-brother."

"All goes well on the bridge?" He felt anxious.

Mura was empathetic for a girl of her age and she knew his moods. "Everything is fine. You would only distract them all, forgive me for saying so, sun-brother."

He sighed. "And so we go to war."

"They tell me you can see it from here. The fleet." She scanned around the sky—every photon passed by the observation deck blister was heavily processed—and pointed to a cluster of starlike points, far away above the sunscape. "There they are."

The lights grew in size and spread apart a little; Folyon saw now that they were splinters, like matchsticks, each with blazing fire at one end. "An enemy fleet from Alpha Centauri, come all the way to the sun. How remarkable."

Mura counted. "Five, six, seven, eight—all accounted for. And their GUT drives are firing./I This was celestial mechanics, Folyon knew; if you entered the solar system from outside perihelion was energetically the most advantageous place to dump excess velocity. "They will come close; the projections of their trajectories are good," Mura said, sounding tense. "And they will come on us quickly. The moment of closest approach will be brief. But the systems are automated—the reopening of the wormhole won't rely on human responses." She hesitated. "Did you tell Lieserl what is happening today?"

"I thought it was my duty," he murmured. "She will remember all this, after all, long after the rest of us are dust. I wonder if they are praying."

"Who?" Mura asked.

"The crews of those ships. For they worship Sol too, do they not? And now we are about to use Sol itself to kill them." He lifted his face, and his old skin felt fragile in the sun's processed light. "Do we have the right to do this? Does even Shira?"

She grabbed his arm. "Too late now—"

The ships exploded out of the distance. And at closest approach solar gases hosed from the drifting wormhole Interface, turning it into a second, miniature sun. Solar fire swept over the invaders. Mura whooped and punched the air. Folyon was shocked and troubled.

Oort Cloud, outer Sol system

Densel Bel wished he could see the sun, with his naked eye. After all, he was among the comets now, within the sun's domain.

He stood in the dark, peering up at the zenith, the way the ship was flying; he tried to imagine he was rising in some spindly, superfast elevator. A light-week out from Sol, with the ship travelling at less than two per cent below lightspeed, the view from the lightdome of the Fist Two was extraordinary. All was darkness around the rim of the hemispherical lifedome. The only starlight came from a circular patch of light directly over his head, crowded with brilliant stars, all of them apparently as bright as Venus or Sirius seen from Earth. He knew the science well enough; the starfield he saw was an artefact of the ship's huge velocity, which funnelled all the light from across the sky into a cone that poured down over his head, even from stars directly behind the ship as it flew.

And meanwhile the stars he was able to see were not the few thousand visible in solar space by the naked human eye. His extraordinary speed had imposed a Doppler effect; the stars behind had been redshifted to darkness, while the 'visible' stars ahead, including the sun, had similarly been blueshifted to obscurity. But conversely red stars, giants and dwarfs pregnant with infra-red, now glowed brightly, crowding the sky, a hundred thousand of them, it was thought, crammed into that tight disc.

Sol itself was somewhere in there, at the dead centre of his visual field, and he knew that the navigators on the bridge had elaborate routines to disentangle the relativistic effects from the starfield. But a primitive part of him longed just to see the sunlight again, with his own unaided eyes, for the first time in so many decades—

Snow sparkled over the lifedome, gone in an instant. He flinched, half-expecting the blister to crack and crumple over him. He called, "What was that?"

A Virtual of Flood appeared in the air before him, the avatar // used by the ship's AI to communicate with the crew. "We lost Fist One," Flood said bluntly.

"How?"

"A dust grain got it. The earthworms. They blew up an ice asteroid in our path, creating a screen of dust hundreds of kilometres wide. We have defences, of course, but not against motes that size, and at such densities. At our velocity even a sand grain will hit with the kinetic energy of a—"