Deep in the Segmentum Obscurus, within the lightless void bordering the Chinare and Cadia sectors.
A gargantuan vessel, so massive it generated its own gravitational waves, struggled through the interstitial veil between realspace and the warp.
It looked utterly battered. Its outer armor plates were a mosaic of scorched ablation marks and jagged craters. Yet, the ship pushed onward, its engines a continuous, defiant roar.
Its name was the Ironhatch (King of Explorators), the Ark Mechanicus of Belisarius Cawl.
Many assume an Ark Mechanicus is simply a larger ship built by the Adeptus Mechanicus, but that is a fundamental misunderstanding. In essence, an Ark Mechanicus is a mobile "Forge World." Within its hull lay not just engines and turrets, but entire industrial assembly lines, great forges, and even genetics laboratories.
The original purpose of building Arks Mechanicus was to venture to the galactic rim in search of lost STCs (Standard Template Constructs). Because these journeys were long and perilous, the ships had to be self-sufficient—capable of waging war, mining asteroids, producing their own munitions, and forging repair parts all at once.
At this moment, this mobile industrial base was in an awkward state of navigation. It wasn't submerged deep in the warp, nor was it crawling through realspace solely on plasma thrusters. Instead, it was "skimming."
Every few minutes, the massive hull would flicker, cutting briefly into the warp to traverse several light-years before snapping back into reality to cool its engines, recalibrate coordinates, and dive again. This method was agonizingly inefficient, placing extreme stress on the engines and hull integrity while inducing severe nausea and vertigo in the crew.
But Cawl had no choice. The current "traffic conditions" in the warp were atrocious.
In the final moments of the 41st Millennium, the Eye of Terror—that great warp-rift in the galactic north—was undergoing violent spasms. The warp storm known as the "Screaming Vortex" was expanding frantically, and other currents of chaos were tearing at the veil of reality. To attempt a long-distance warp jump now, even for an Ark protected by top-tier Geller Fields, was to invite a high probability of becoming permanently lost.
Thus, Cawl could only use this "short-jump-and-glide" maneuver, scraping along the edges of the storm.
Inevitably, the ship's destination was Cadia: the breakwater of the Imperium and the final force plugging the Eye of Terror. Cawl knew that Abaddon the Despoiler was making his move; the 13th Black Crusade was imminent. He had to reach the Cadian Sector before it was too late.
In the core meditation chamber deep within the battleship, Belisarius Cawl, Archmagos Dominus of Mars, was suspended from a massive anti-gravity life-support rig.
His body had long ago shed its human silhouette. He resembled a giant metallic centipede; his lower half was a mass of countless mechanical limbs, while his upper torso was bristling with data cables and servo-arms. He was busy—extraordinarily so. One might even call him one of the busiest beings in the galaxy.
His brain (if it could still be called that) was simultaneously processing thousands of high-intensity computational tasks. Cawl's most "monstrous" trait wasn't just that he had lived for ten thousand years, but that he had turned himself into a multi-threaded supercomputer.
He had partitioned his consciousness into several independent sub-personalities. These avatars shared one body but thought independently. For instance, Cawl-Inferior managed engine output, Cawl-Superior pondered ultimate philosophical questions, and Cawl-Archivist organized memories from ten millennia ago. This multi-threading allowed him to do the work of an entire general staff and research institute by himself, though it also made him appear like a schizophrenic.
Currently, the bulk of his processing power was occupied by an extremely complex set of data models. This data originated from the El'shad system in the Chinare Sector, from which the King of Explorators had recently returned.
There, he had engaged in a... "not entirely friendly" academic exchange with a certain famous collector and Necron Overlord: Trazyn the Infinite. While Trazyn was technically a thief, he did possess an impressive collection. From him, Cawl had secured core parameters regarding "Blackstone Pylons" and a batch of controlled Canoptek Scarabs.
Blackstone Pylons were "Warp Suppressors" built millions of years ago by the Necrontyr. With proper frequency tuning, they could emit anti-psychic beams to push back warp energy and calm realspace. Cawl's plan was simple: learn how to build them, or at least how to use them. If the Eye of Terror was leaking, he would use Blackstone to stitch the hole shut.
On the holographic projection, the frequency models of the Blackstone Pylons shifted wildly. Three of Cawl's sub-consciousnesses were locked in a heated argument over a single parameter.
"The frequency is wrong! Setting the wavelength to 400 nanometers will trigger a reverse collapse!" argued Cawl-Calculus.
"That's because your model is flawed! Trazyn's data is raw; it must undergo human logical transcoding!" countered Cawl-Analytic.
"Stop arguing! Hull shield energy has dropped another 30%. Recharge the shields first!" interjected Cawl-Captain.
Cawl's primary consciousness suppressed the noise. He had to understand the principles of the Pylons as quickly as possible. Necron technology followed an entirely different path than human tech; they mastered the ultimate laws of physics. Though he had the data—and had paid a price for it—he was still a long way from fully mastering Necron science.
Cawl didn't just manage research; he managed logistics. His gaze pierced through dozens of deck levels to the lowest reaches of the King of Explorators, into a vast stasis chamber zone. Thousands of silver hibernation pods were lined up in neat, endless rows.
Inside lay the giants known as "Primaris Space Marines"—Cawl's secret nest egg, hidden for ten thousand years.
Shortly after the Horus Heresy, during the dawn of the Imperium, Roboute Guilliman had given Cawl a task: build a better Space Marine. Cawl had spent ten thousand years doing just that—producing tens of thousands of them.
Primaris Marines were taller and stronger than the old Astartes, implanted with three new organs (the Sinew Coils, the Magnificat, and the Belisarian Furnace). They were Cawl's ultimate trump card for saving the Imperium.
One of Cawl's servo-arms was remotely operating a mechanical limb on the lower decks, fine-tuning a set of newly produced power armor. The MK X Tacticus Armor was a major overhaul of the Astartes equipment system. Unlike the clunky, rigid models of the past, this armor featured smoother lines and more flexible joints. Most importantly, it was modular.
Older marks, like the MK VII or MK VI, had fixed roles. But the MK X was different. Need stealth? Swap in the "Phobos" light components. Need a frontal assault? Bolt on the "Gravis" heavy plates. Cawl's modular design vastly increased tactical flexibility.
Of course, to many conservative Tech-Priests and Chapter Masters, this was blatant heresy. They believed the Emperor's design was perfect and immutable. Cawl didn't care. His only metric was: does it work?
"The bolt rifle's feeding mechanism is still a bit stiff..." Cawl muttered. "Return spring tension can be increased by 8%, but it requires a higher grade of lubricant. Note: Seek high-purity nano-lubricant in the next resupply."
Just as Cawl was immersing himself in the joy of research and repair, a series of hurried footsteps interrupted his thoughts. The meditation room doors hissed open.
A young-looking Tech-Priest entered. Unlike others who modified themselves into half-human, half-ghostly apparitions, he retained most of his human features and had a rather likeable face. He wore clean robes and held a data slate.
Friedisch Adumm. Or, according to Cawl's internal numbering: Adumm-87.
This Adumm was no ordinary man. He was an old friend of Cawl's from the Great Crusade era. The original Adumm had died during the Horus Heresy, but Cawl was sentimental. He didn't want to lose his friend, so he used illegal cloning technology to repeatedly resurrect him—cloning a new body and downloading the memories whenever the previous one died.
While this flagrantly violated Imperial laws regarding "Abominable Intelligence" and "False Life," on Cawl's ship, the right of legal interpretation belonged to Cawl. Because of this, Adumm was the only person on the King of Explorators who dared to talk back to Cawl, snark at him, or even curse him to his face.
Adumm walked to the life-support rig. He didn't bow; he simply tossed the data slate onto a table.
"Belisarius, we have trouble."
Adumm's voice sounded exhausted, clearly worn down by the mounting disasters.
"If it's about the shield energy consumption, I already know," Cawl said without looking back, his servo-arms continuing their work.
"It's not just the shields—" Adumm sighed. "Specifically, it's energy and materials. Our void shield generators burned out two more core coils during the last jump. We're out of spare parts. And to maintain this 'skimming' flight, reactor fuel consumption is five times the normal rate. If we don't find high-purity adamantium and plasma fuel soon, we won't make it to Cadia. We'll just be high-end space junk drifting halfway there."
The ship was indeed in dire straits. Before arriving here, they had fought a war against Orks in the El'shad system. The Orks' suicidal tactics, combined with the forced transit through warp storms, had devastated the ship's shield systems. Though the Ark could manufacture parts, it couldn't conjure raw materials out of thin air. One cannot forge without metal.
Cawl finally turned around. His metallic face, crowded with electronic eyes and sensors, looked at Adumm.
"I have already dispatched the sub-vessels," Cawl's synthesized voice replied, devoid of emotion. "Our frigates and destroyers are performing wide-spectrum scans of nearby systems. If they find valuable minerals or abandoned ships, they will bring the resources back."
Many of an Ark's sub-systems were independent. When it needed to "feed," it released the smaller ships in its belly to scavenge. Whether it was ore from an asteroid belt or the wreckage of some unlucky starship, if it was useful, they took it.
"And the scan results?" Adumm asked.
"Mostly trash," Cawl replied. "The barrenness of this sector is appalling. Only radiation-soaked wasteland worlds and a few dead planets already picked clean. The only interesting signal comes from the neighboring Agripinaa Sector, but it's currently crawling with Orks. The cost of fighting through them is too high; the fleet must bypass it."
Adumm rubbed his temples.
Cawl asked, "What is the status of communications? Any distress signals or trade requests? Perhaps we can strike a bargain with a local Governor for resources."
At the mention of communications, Adumm's expression darkened further.
"That's an even bigger headache." He pointed to a folder on the data slate. "See for yourself. The warp communication channels are currently a madhouse. It's all screaming, static, and daemonic whispers. Three of my astropaths have already gone insane; the rest are on the brink of collapse."
At this point in time, interstellar communication was a high-risk profession. Warp storms were tearing at reality, causing all psychic messages to be riddled with interference. You might try to send "Hello" and it arrives as an insult; you might try to receive a weather report and get the moans of a Slaaneshi daemon instead. Filtering useful coordinates or intelligence from this mountain of garbage was like finding a needle in a cosmic haystack.
"Most of it is meaningless agony," Adumm said, flipping through records. "'My God, there's a daemon here,' 'The cathedral collapsed,' 'My cat turned into a tentacle monster'... we get thousands of these per second. Our filtering algorithms are overloaded."
Cawl fell silent for a moment. "Continue filtering. Set keywords: STC, Blackstone, Ancient Tech, High-Energy Signature. We do not have the time or the obligation to save ordinary mortals. We only care about what helps us repair this ship and complete the 'Great Work'."
Adumm curled his lip. "You really are cold, Belisarius."
"It is called being pragmatic." Cawl turned back to the power armor. "The Primarch is still sleeping. If we do not wake him, if we do not hold Cadia and stitch that damned Eye shut, everyone dies eventually. I am not saving them now so that I can save more of them later."
The Primarch Cawl referred to was, of course, Roboute Guilliman. Struck by Fulgrim's poisoned blade ten thousand years ago, he had been held in a stasis field ever since. Most believed him dying, but Cawl had a mad plan to bring him back. All of Cawl's efforts—the Blackstone research, the Primaris project—were ultimately to pave the way for the Avenging Son's return.
"Fine, you're right," Adumm shrugged, knowing he couldn't move the stubborn old man. "I'll go back to staring at the crazed astropaths and try to get some work out of them before their brains boil. Also, the shield generators only have 130 hours of high-intensity operation left. You'd better pray your sub-vessels bring back good news."
Adumm turned and left the chamber. The doors sealed, returning the room to the silence of humming machinery.
Cawl wasn't anxious. Anxiety was useless. Instead, he reallocated his processing power. The Cawl-Explorer avatar took over the scanning arrays and expanded the search radius. The beams, which had been focused on major shipping lanes and Forge Worlds, now swept into the forgotten, peripheral corners: second-rate worlds at the map's edge, abandoned mines, and dangerous nebulae.
The Ark Mechanicus's sensors ramped up to full power, like a giant eye opening in a dark forest, greedily searching for any flicker of light—even if it came from an insignificant scrap yard, weak as a candle in the wind. If it bore the signatures Cawl desired—high-purity matter, anomalous energy, or familiar Golden Age coding—he would strike like a shark sensing blood.
"Explore... explore..."
Cawl's data streams extended into the void.
Suddenly, a mockingly deep, synthesized voice crackled through: "Amateur mon-keigh, it looks like you're in trouble."