Red Star (The Triple Stars, Volume 2)

said to Surtr, speaking out loud.
“I have no information on its function,” the entity replied.
“Is it active? Have you ever seen it do anything?”
“Nothing.”
She had to resist the urge to kick the Aetheral, goad it into some sort of inquisitiveness. How could it have been here all this time and not wondered?
“How does this let us communicate with the outside galaxy?” she asked. “Is this the opening of a metaspace tunnel?”
“I do not know,” the entity replied.
“It was built by the Tok?” Ondo asked.
“They all were.”
“What do you mean by all?”
“There are seven them in a shell around the star.”
“Are they identical to this one?” Ondo asked.
“Yes.”
“Why are there seven? Why did they need more than one?”
“I do not know,” said Surtr once again.
“I think I do,” said Selene to Ondo over their private link. She'd been studying the scraps of telemetry she was starting to pick up from the other objects. They did, indeed, orbit in a sphere around the dense, cold body of the star. Its gamma ray bursts were a blinding distraction in her left eye, lighting up local space with their staccato flashes. But, from their radiation, she was picking up echoes of the other orbital megastructures. Each stood at roughly the same distance from the stellar remnants.
The objects rotated on their own axes, giving anyone standing upon the inner or outer surfaces of their cones a rapid day/night cycle. She could discern a clear pattern to the movements of the cones relative to each other; they were coordinated, their orbits swirling in a complex but predictable dance around the ghost of the star. They were like, she thought, the brushes of an artist moving across the surface of a canvas, able to reach every point on the surface, following some purpose that she couldn't fathom.
She showed what she'd picked up to Ondo. “Before the supernova, this object, all of these objects, would have been very close to the surface of the star. In fact, I think it's likely they would have been touching the photosphere, or may even extending inside it. I don't begin to understand how that's possible – there's no way solid matter could withstand the temperatures and pressures involved – but that's what I'm seeing.”
Ondo said, “Assuming they used materials capable of that, matter whose physics we don't understand, then it's very likely these devices were the engines of the stellar engineering.”
“That has to be it,” said Selene. “They shunted matter in through metaspace pathways like the one we walked down, giving the star more and more mass and increasing its gravity until it collapsed and went supernova. The movement patterns to the objects must have been added so that the matter was distributed evenly, woven into the structure of the star.”
“It's incredible, but I agree, that's the most likely explanation.”
“Something similar must have been worked at the Haven's blue dwarf, which was how a seemingly-impossible star came to exist.”
Ondo took a step forwards, as if it would enable him to pick out more data from what they were seeing. “That would suggest the other end of the tunnels would be at or near other stars. Donor stars. They siphoned mass across the galaxy to alter suns as they saw fit.”
“It wouldn't have to be a star,” she said, “although that might have been easier. What I mean is, more tenuous accumulations of donor-matter like interstellar dust would work as well; they'd just make the shunting process a lot longer.”
“I wish I understood more about this,” said Ondo. “Setting aside how such structures could be built, how did they control the pressures so that matter flowed in the required direction?”
“No idea, but my guess is the mass-relocation mechanism explains the nebula, too,” said Selene. “If they were capable of tripping a regular sun into a premature supernova, they could also have built the nebula by sucking gas and dust from one part of the galaxy and placing it here to form a cloud centred upon the dead star. Or perhaps they carefully timed the two events so that the nova triggered the nebula, like a spark igniting a flame.”
“The technology required for it all is unimaginable,” said Ondo. “This nebula extends for tens of light-years.”
“It's incredible, sure,” said Selene, “but it's not unimaginable since we're both imagining it right now. You're the one who likes to believe the galaxy was capable of marvels three hundred years ago. I think we have to accept that this earlier civilisation was capable of even greater things. It seems quite likely to me that the Coronade culture only existed because it was able to make use of the ancient technology it had uncovered.”
“But, engineering the creation of a nebula, Selene? Why would this supposed race go to such extraordinary lengths?”
“Who knows? Maybe this is a work of art on a vast scale. It is undoubtedly beautiful. They used these megastructures to paint space with plasma clouds, sculpt the structures they wanted upon the void. Or, maybe the nebula is a beacon, shining out to warn people because this is a region of Dead Space. It's a lighthouse saying, stay away; it's not safe to come here. For all we know, the cloud structures spell out a dire warning in some unknown alphabet. Or, as you once suggested, the region might be culturally or religiously important in ways we can't begin to understand. I don't know. Not knowing why doesn't mean it cannot be true.”
They were manoeuvring now, the ship's vector taking them away from the dwarf star and curving into the gaping mouth of the structure. The interior contained only shadows. The edge of the cone, she now saw, was serrated. Edged with a line of teeth.
“I can't work out the scale of it,” said Ondo. “I keep thinking we're approaching the surface of it, but then we don't reach it. It feels like we're shrinking as we fly into it.”
“It's an optical illusion. This thing is big, but it's hard to get a sense of