Chapter 6: The Core
Table of Contents
It hung in space approximately two kiloparsecs from Sagittarius A*, in a region of unusual gravitational calm — a cosmic eddy in the turbulent currents of the galaxy’s core. The local stellar environment was dominated by old, stable K-dwarf stars, their slow-burning patience providing steady illumination across billions of years.
Nolan stood at the observation port and felt the weight of twenty-five years settle into the moment.
This was where the thread ended. The convergence paper — his and Ren’s, the work that had cost him seven years on Deimos and bought him the ship that carried them here — had predicted this: a central origin node, the root of the Lacework, the place from which the network had been built outward across the galaxy. Ten hops. Four months. Every wormhole growing older and larger, every biological sample growing more complex, every piece of data confirming that the builders were here, at the center, waiting at the end of the longest thread any human being had ever followed.
He had imagined this moment so many times that reality felt like memory. Standing in the observation bay of the ship he had designed, looking at the place where the Gardeners lived — or had lived, or had left behind whatever a post-biological intelligence left behind when it moved on. The answer to the question that had driven him since a Tuesday night in September 2133, when a pipeline on a ranch in Wyoming had found a signal in the noise and his life had acquired its final, irrevocable direction.
The core was unmistakable.
Wormhole mouths arranged in a precise geometric configuration around a central void. The instruments resolved them in order of proximity, and the first eleven showed the familiar Lacework signatures: gravitational lensing, thermal whisper, the shimmer of exit-mouth starlight. Each connected to a major Trunk Line feeding outward into a different region of the galaxy. Together, they formed the root system of the Milky Way’s Lacework — every thread converging here, every river finding the sea.
“Eleven trunk connections,” Ren reported, his voice carrying the particular tension of a scientist watching theory become geography. “Geometric distribution consistent with optimal routing for the galactic disk. Every major arm and region represented.” He looked up from his console. “It’s the origin node. Exactly where the convergence paper said it would be.”
Maren was at the data console, her stylus tracing the hub topology in the tablet’s margin with the unconscious precision that meant her mind was running ahead of her hands. “The construction signatures are the oldest we’ve seen. These Throat Engines predate everything in the outer network by at least a billion years.” Her voice was quiet with satisfaction — the quietness of a woman standing inside a building she had designed from blueprints and finding it exactly the right shape.
Nolan looked at the eleven mouths arranged in their geometric perfection and felt something he had been waiting to feel for a quarter of a century: arrival. The topology confirmed. The convergence proven. The central node, real and ancient and here, exactly where the data had always said it would be.
For a moment — a brief, suspended moment that would later feel like the last comfortable breath before a plunge — the crew of the Thread stood at the center of the galaxy and believed they had found what they came for.
Then Yuki said, “There are more.”
She had been running a full gravimetric survey of the hub’s perimeter — standard protocol, the systematic sweep she performed at every new node. The eleven Trunk Line mouths were clustered in a region roughly a light-day across, their geometric precision suggesting a single coordinated construction event. But beyond that perimeter, farther out, three additional gravitational signatures had resolved on her instruments.
They were enormous.
“Three additional wormhole mouths,” Yuki reported. Her humming had stopped — not the gradual trailing off of distraction but the sudden silence that the crew had learned to associate with findings that frightened her. “The scale is…” She rechecked her readings. Rechecked them again. “These are an order of magnitude larger than the Trunk Lines. The nearest one is roughly five kilometers across. The second is comparable. And the third —” She pulled the data up on the main display. The numbers sat on the screen with the mute authority of things that refused to be misread. “The third is nearly fifteen kilometers in diameter.”
Fifteen kilometers. The largest intragalactic Trunk Line they had transited was three kilometers wide — itself a cathedral of engineered spacetime that had made the crew feel like ants crossing the nave. Fifteen kilometers was not a wormhole. It was a gateway built for something that thought on a completely different scale.
Nolan stared at the display. His sense of arrival — the comfortable certainty of a man who had reached his destination — was already cracking, though he could not yet have said why. The eleven intragalactic Trunk Lines matched the convergence model perfectly. Three additional mouths, vastly larger, matched nothing.
“That’s not a Trunk Line,” Ren said slowly. He was already pulling spectral data from the three anomalous mouths, running the stellar population analysis that had become routine at every node — matching the stars visible through each throat against galactic models to determine the exit mouth’s location. The calculation took seconds. He ran it again. And again.
“Ren?” Herrera, watching from the command station.
“The stars through the Trunk Line mouths are consistent with known galactic regions. Expected. Standard routing.” Ren’s voice had gone flat — the particular flatness it assumed when humor was no longer available as a defense. “The stars through these three are not.”
He put the analysis on the display. Three spectral profiles, three populations of stars visible through three enormous wormhole throats. None of them matched any stellar population in the Milky Way’s disk, bulge, halo, or satellite galaxies. The metallicity distributions were wrong. The color-magnitude diagrams were wrong. The density patterns implied galactic structures at angles that corresponded to no possible vantage point within the Milky Way.
“I’ve run it against every quadrant, every arm, every known globular cluster and satellite,” Ren said. “There is no orientation within this galaxy that produces these star fields.”
The silence that followed was of a different quality than any silence before it on the voyage. Not the awed hush of discovery. Not the productive quiet of scientists processing data. The silence of people watching a foundation shift beneath them.
“They’re not in the Milky Way,” Maren said. Her stylus was motionless on the tablet’s surface — and Nolan, who had learned to read Maren’s hands the way a sailor reads wind, understood that the stillness meant something had broken in her model. The mind that never stopped building was, for the first time in his experience, stopped.
“Extragalactic,” Ren confirmed. His voice was barely above a whisper. “All three. They connect to other galaxies.”
No one moved. The word hung in the observation bay with the weight of a door swinging open onto a room no one had known existed in a house they thought they’d mapped.
Extragalactic.
The convergence paper — Nolan’s paper, his life’s work — had traced the Lacework’s topology to this point. The central origin node. The place where the builders lived. The root of the tree. The entire mission had been built on a single elegant assumption: that the wormhole network began here, at the heart of the Milky Way, constructed outward by an intelligence that called this galaxy home.
Except the tree had deeper roots.
The Milky Way wasn’t the source. It was a node. A way station. Everything they had followed — the convergence gradient, the age correlation, the biological gradient pointing inward, the topology that had seemed so clearly to say the builders are here — pointed to this hub, yes. But the hub itself pointed somewhere else. Three of its doors opened onto other galaxies, and one of those doors was the largest engineered structure any human being had ever seen, and it was aimed at a destination that was not in the Milky Way, had never been in the Milky Way, and might be farther away than anything Nolan had allowed himself to imagine.
The builders were not here. They had never been here. This galaxy, with its billions of stars and its carefully threaded Lacework and the life seeded on thousands of worlds across a hundred-thousand-light-year disk — all of it was downstream. A garden tended from a distance so vast it was measured not in light-years but in the spaces between galaxies.
Nolan felt something he had not felt since the UN rejection letter: the cold shock of a destination receding. Not disappearing — the flagship gate was right there, visible through the viewport, its colossal mouth shimmering with the light of alien stars. But receding, the way a mountain recedes when you crest what you thought was the final ridge and see the true summit for the first time, higher and farther than the map suggested, the scale of the remaining climb suddenly, sickeningly clear.
“The builders aren’t here,” Adaeze said. Her voice was careful, measured — the voice of a scientist stating a conclusion she was still verifying against her own disbelief. “This hub was built by something that was already out there. The Milky Way was seeded. The entire galaxy. Not just the habitable worlds — the entire network. From somewhere else.”
“My framework allows for it,” Maren said, and the admission cost her something visible. She had mentioned intergalactic propagation in her published papers — the theoretical possibility that seed signals could cross between galaxies at the speed of light, bootstrapping new networks in every galaxy they reached. Hundreds of millions of years between galaxies, she had said in the Thread’s common room, with the calm of a mathematician stating a theorem. But there was a vast difference between acknowledging a theoretical possibility in a paper and standing at the center of your own galaxy and realizing it applied to you. That the Milky Way, in the topology of the network, was not the origin. It was a leaf.
She looked at the three enormous mouths on the display, and Nolan saw in her face something he had never seen there before: the expression of a person who had spent a decade predicting the architecture of a building and had just discovered it was one room in a city.
“I need time,” she said.
It was the first time on the voyage she had asked for it.
They spent two weeks at the core hub. The science demanded it — fourteen wormhole mouths to characterize, the oldest Throat Engines in the Milky Way to study, the densest gravitational wave environment they had encountered to map. The Throat Engines here were the oldest they had seen — Yuki estimated their construction at roughly four billion years ago, just as the first stirrings of life were beginning on Earth. They were also the most sophisticated: metamaterial structures organized at scales that suggested mastery of quantum gravity, materials whose properties Yuki could measure but not explain.
Yuki spent days on the flagship gate itself. “The great wormhole is actively maintained,” she reported. “Not the slow, stable oscillation of the Lacework’s internal connections — this is a deep, powerful pulse. An active entanglement tether, still functioning, still generating the quantum stress-energy to hold open a throat wide enough to fly a city through.” She paused on the detail that mattered most. “The energy is flowing from the other side. Something on the far end is sustaining this connection. It’s not dormant. It’s not residual. It’s tended.”
Something on the far end. Something still active, still maintaining a fifteen-kilometer wormhole across intergalactic distances, still holding the door open after four billion years. The implication settled over the crew like a change in atmospheric pressure — not immediately dangerous but impossible to ignore.
But it was the two weeks that Maren needed, and she used them.
On the fourth night at the core hub, she walked the Thread’s corridors at three in the morning — as she always did, tablet in hand, stylus moving in the margins. But tonight the margins were not filled with the unconscious sketches of topologies she had already predicted. Tonight they were filled with something new: the framework she was extending in real time, in response to data that had outrun her model for the first time in a decade.
She stopped in the observation bay. The flagship gate hung in the viewport, enormous, its Throat Engines pulsing with the slow rhythm of quantum vacuum fluctuations, the stars of another galaxy shimmering through its throat.
She looked at it for a long time. Then she looked down at her tablet, where the equations had been assembling themselves for four days with the patient inevitability she had learned, across a career of theoretical work, to recognize as the signature of a correct proof converging.
The framework extended. Of course it extended.
The seed signal propagation mechanism she had described in her published papers — electromagnetic transmissions carrying compressed blueprints, bootstrapping Throat Engines at each destination, each new hub becoming a launcher for signals to more distant targets — was not limited to intragalactic distances. She had written about it herself. But she had not followed the logic to its structural conclusion: that if the mechanism worked between stars within a galaxy, it would produce the same self-similar topology between galaxies across the cosmos. That every galaxy touched by a seed signal would build its own internal Lacework and construct a core hub with connections pointing outward — or rather, inward, back toward the signal’s origin. That the pattern she had predicted at the intragalactic scale would repeat, with elegant inevitability, at the intergalactic scale. Hubs within hubs. Networks within networks. The same architecture at every level of magnification, converging on a single point that might be one galaxy away or a hundred, but that was findable — necessarily findable — because the architecture itself was the map.
She had predicted the building. The building was a room in a city, and the city was a district in a nation, and the nation was a province in an empire built from galaxies.
She presented her findings to the crew the next morning, gathered in the common room with the flat, recycled coffee that Yuki’s synthesizer produced with a consistency everyone appreciated and no one enjoyed.
“My published framework predicted the intragalactic topology,” Maren said. She spoke carefully, the way she always did when the mathematics was sure but the implications were not yet fully metabolized. “What I failed to extend — what none of us extended — was the prediction to the intergalactic scale. The data forced it.” She pulled up the hub topology on the display: eleven intragalactic mouths, three extragalactic ones.
“Two of these are lateral connections — links to neighboring galaxies within the Local Group. Standard mesh connectivity for routing resilience, the same pattern we see between star clusters within the Lacework.” She highlighted the two five-kilometer mouths. “But the third is something else.”
She brought the flagship gate’s profile onto the screen. Fifteen kilometers. Stabilization energy dwarfing the others by an order of magnitude. Throat Engines the size of small planets.
“This is a flagship trunk line. The energy budget to maintain a throat that size across intergalactic distances means it’s reaching much farther than the Local Group. And it’s oriented along the propagation axis — pointing backward along the path the original seed signal traveled to reach the Milky Way.” She paused to let the geometry speak for itself. “It doesn’t connect to the galaxy next door. It connects to a hub several generations closer to the origin of the network. The same self-similar structure that organizes the intragalactic Lacework, repeating at the intergalactic scale.”
She looked around the room. “Follow the largest gate at every hub, and you converge on the origin. It’s the same principle that brought us here from 97 AU. It works at every scale. You don’t need a map. You just follow the current.”
“And how many hubs?” Herrera asked. The question beneath the question was: how far?
Maren was honest. “I don’t know. The intragalactic journey was ten hops. The intergalactic hierarchy could be shallower or deeper — it depends on how far the network has propagated and how many generations of galaxies lie between us and the origin.” She met Herrera’s eyes. “The topology tells us the direction. It doesn’t tell us the distance.”
The gravitational wave data told them something else.
Yuki had been running her own analysis in parallel, and what she reported next was the detail that changed the calculation from theoretical to urgent.
“The signal doesn’t terminate here,” she said.
She put the data on the display. The torrent she had been tracking across twelve intragalactic hops — the structured flood of encoded information flowing inward through every wormhole, growing denser and more complex at each successive node — was here at the core hub denser than anything they had encountered. Not a pulse now but a continuous roar, structured and layered and saturating her instruments. But it did not pool. It did not converge on the hub and stop. It flowed through the hub and into the flagship gate — a river of data pouring into the throat of the fifteen-kilometer wormhole and disappearing toward whatever lay on the other side.
“This hub is a relay,” Yuki said. “The entire Milky Way’s Lacework — every wormhole, every seeded world, every piece of gravitational wave telemetry from every node in the network — is feeding data through this point and out through the flagship gate to somewhere else.” She looked at the crew. “Whatever is receiving this data is not here. It’s on the other end of that wormhole. And it has been receiving it for four billion years.”
“Someone is there,” Adaeze said.
“Or something,” Ren added. His voice carried the weight of a man who had spent a career mapping a river system and had just discovered the ocean.
Adaeze was quiet for a moment, looking at the hub topology on the display — eleven arteries feeding inward from the galaxy’s Lacework, three connections reaching out to other galaxies, the flagship gate pointing toward a destination they could not see. She was thinking about a question an astrophysicist had asked in the Meridian’s galley, sixteen years ago, on the day the crew had confirmed that life across the galaxy shared a common origin: If the bridges connect what grows from the seeds, what happens when what grows isn’t friendly?
She had carried that question since Viridis. It had been a question about the Milky Way — about the civilizations that might arise on seeded worlds within a single galaxy and find each other through the Lacework. The extragalactic mouths changed the scale of the question in a way that made her chest tighten. The network didn’t connect worlds within a galaxy. It connected galaxies. Billions of seeded worlds across multiple galaxies, all linked, all reachable through a system of doors that did not choose who walked through them. The pool of potential travelers — friendly and otherwise — had just expanded beyond any estimate she could meaningfully construct.
She did not say this aloud. Not yet. The crew had enough to absorb. But she carried it, the way she carried Ife’s letter — close, and heavy, and impossible to set down.
Herrera called a formal mission review that evening. Not the informal gathering of the common room but a briefing, the kind he convened when decisions could not be deferred.
“This wasn’t the mission plan,” he said. He stood at the head of the common room table, the hub topology still glowing on the display behind him — the fourteen mouths of the core hub, the flagship gate dominating the frame. “We were provisioned for an intragalactic expedition: follow the Trunk Lines to the center, study the origin node, and return. We’ve reached the center. The origin isn’t here.” He let that settle. “Following the flagship gate turns this into an intergalactic expedition of unknown duration, to an unknown destination, through wormholes at scales we haven’t tested. I need to understand what that costs before I can decide whether it’s a cost we can bear.”
Ren had the numbers. “The return through the Milky Way will be significantly faster than the outward journey. We’ve already mapped the route, surveyed each system, catalogued the secondary mouths. If we skip the survey work and transit straight through — no stopping for weeks at each node, just hop and go — I estimate we can compress the intragalactic return from four months to three, perhaps four weeks.” He pulled up the consumables inventory. “That buys us roughly three months of operational margin for the intergalactic leg. Food, water, air processing — all within tolerance for that window.”
“Hull integrity?” Herrera looked at Yuki.
“Ninety-one percent after ten intragalactic transits,” she said. “The Trunk Line wormholes in the Milky Way were within the hull’s design parameters. But the flagship gate is an order of magnitude larger. I’ve been running stress simulations against its throat profile since it resolved on instruments, and the harmonics are different — frequencies the Thread was never tested against.” She chose her words with the care of an engineer who understood the difference between safe and probably safe. “For a single transit, I’m confident. The hull geometry can handle it. But I want to instrument the crossing — full resonance monitoring on every structural member. If we’re going to be transiting flagship gates repeatedly, at potentially increasing scales, I need to know what the harmonics do to us.”
“So we have margin,” Nolan said. “Three months of consumables. Hull well above minimum. And the return through the Milky Way is mapped and fast.” His voice carried a controlled urgency — not the raw hunger that had been visible in the observation bay, but the version of it he deployed when the audience required persuasion rather than revelation. “The signal flows through that gate. The builders — the actual builders, whatever and wherever they are — are on the other end. Everything we came for is through that door.”
“We came for the central hub,” Adaeze said. “We’re here.”
“We came to find the Gardeners.”
“And what if they’re not one galaxy away but ten? Or a hundred?” Adaeze held his gaze. “We have three months of margin, Nolan. Not three years. Every hop through a flagship gate is uncharted. We don’t know the transit distances. We don’t know the conditions. We don’t know what else is traveling these routes.”
Ren leaned back in his chair. “The self-similar topology is our best guide. If Maren’s extended model is correct — and everything she’s predicted at the intragalactic scale has been confirmed — then each hub will have the same structure. Flagship gate pointing inward, lateral links, intragalactic Trunk Lines. We’ll know at each stop what the next hop looks like. We won’t be flying blind.”
Maren spoke last, and she spoke carefully. “I can’t predict how many levels the hierarchy has. But I can predict what each level looks like — the topology, the size scaling, the age gradient. At every hub, the data will tell us whether we can afford the next step.” She paused. “The framework gives us an incremental decision at every stop. We don’t have to commit to the whole journey. We just have to commit to the next hop.”
Nolan said nothing further. He had made his case. The flagship gate hung in the viewport behind Herrera’s shoulder, fifteen kilometers of engineered spacetime, the wrong stars of an alien galaxy glittering through its throat.
Herrera looked at his crew, one at a time. Ren, who had spent a career mapping the topology and wanted to see where it ended. Adaeze, who had catalogued the biology at every stop and carried her daughter’s letter and the astrophysicist’s question from sixteen years ago. Yuki, who wanted to touch the engineering that had rewritten spacetime and who understood, better than anyone, what it would cost the ship. Maren, who had watched her framework shatter and rebuild in four days and who wanted to see if the new model held.
Then he looked at Nolan. The man who had found the first wormhole. Who had built this ship. Who had lied his way aboard the Perspicacity and mapped the Lacework from exile and dragged humanity to the center of the galaxy through sheer, reckless, magnificent obsession. The man Vasik had warned him about. The man who was, at this moment, doing exactly what Vasik had predicted: making the destination seem so urgent, so singular, so close that the only possible answer was yes.
The difference, this time, was that Herrera agreed with him.
Not because Nolan was persuasive. Not because the science was compelling, though it was. Because Herrera was afraid.
The gravitational wave data had changed the shape of his fear. The signal — the structured torrent Yuki had been tracking since 97 AU, the data stream that had grown from whisper to murmur to roar across twelve hops — did not terminate here. It flowed through the flagship gate toward a listener they had not yet found. Whatever had built the network, whatever had seeded the Milky Way, whatever had been patiently collecting telemetry from a billion worlds for four billion years — it was on the other side of that door. It knew about Earth. It had known about Earth since the first seed capsule activated in a Hadean ocean. And Herrera — who had two sons in the orbital habitats above Ceres, who wrote them letters every night in a leather journal he kept in the drawer beside his bunk — could not bring himself to go home without knowing what was watching his world.
The thread had not ended. It had crossed a threshold that none of them had anticipated. Nolan wanted to follow it out of hunger. Herrera wanted to follow it because the alternative was to go home blind — to a planet connected to a network it did not understand, monitored by something it had never met. Every instinct he had as a captain, as a father, told him that ignorance was the greater danger.
“Take us through the big one,” Nolan said.
A beat of silence. Herrera weighed the science, the risk, the crew, and the thing he could not quantify — not the pull of the unknown, which he felt as strongly as any of them and trusted less, but the weight of what the unknown already knew about them.
“Take us through,” he said. “Yuki, full instrumentation. I want every number.”