"Guilliman, thank you for your hard work," said Guidos with a respectful nod.
Guidos had been selected from among the psykers willing to serve under the Primarch. His duty was to maintain the cloned mind of the Archmagos Dominus Belisarius Cawl, buried deep within the sanctum of the Glory of Macragge. This particular section was kept highly classified. Even the most trusted loyalists, such as Captain Sicarius, were denied unrestricted access.
"It is my highest honor to serve you, my lord," Guidos said, his milky-white eyes shining with reverence.
"Your loyalty is appreciated. Let us begin. I need to review the message Cawl sent. I must assess the strategic situation," Guilliman replied.
Guidos nodded, turning silently into the darkness. Guilliman followed closely.
As they proceeded deeper into the vault, the air grew increasingly stifling. The oppressive heat from the hidden machinery intensified, and a low humming vibrated through the walls. With each step, a wave of psychic pressure bore down on Guilliman, as though the Warp itself were testing his resilience.
Suppressing his discomfort, he marched behind Guidos until they arrived at a massive sealed door.
The door was unlike any standard Imperial design. Three overlapping layers of tortoise-shell-patterned plating, each nearly a meter thick, formed a tightly interlocked barrier.
Guidos cracked the first layer open slightly. Guilliman stepped forward for identity verification.
A red beam scanned his eyes.
"Retinal scan confirmed."
From the steel walls, mechanical arms extended. They conducted further scans of Guilliman's body, mind, and soul, ensuring that nothing had compromised the Primarch's being. Only after full verification did the door open completely.
The room beyond was steeped in darkness.
"Illumination," Guidos commanded.
Ceiling-mounted machines stirred to life. White lights flickered on, one after another, illuminating the chamber.
Ten closed panels lined the walls at eye level. Overhead, metal-reinforced pipes hung tightly bound in place.
"Cawl's psychic transmission was unusually muted," Guidos said, walking further in. "It lacked the organic flare typically found in Warp-linked communication. I suspect he used a machine to encode and transmit the message. Once, I believed such a feat impossible. But I must concede—he's a master."
"That doesn't surprise me," Guilliman said with a shrug. "Without my own database, Cawl would easily be the most learned human alive."
Cawl had survived ten millennia—an inconceivable span of time. Most of the human Immortals perished or vanished during the Horus Heresy. Of those who remained, Cawl was likely the longest-lived.
"The message is clean. No taint, no corruption, not even the usual distortion caused by the Great Rift. Cawl's communication is unblemished, and his transmission technique is invaluable. The Great Rift's emergence altered everything. Our very survival hangs in the balance."
"That will change, Guidos. I promise," Guilliman said.
"I believe you, my lord." Guidos stepped up to a towering machine embedded in the wall.
"By the will of the Omnissiah, initializing sequence."
Leaning on his staff, he spoke the activation phrase.
The curved wall let out a soft creak, followed by the grinding of gears and shifting panels.
Detection beams fanned out from the walls, bathing both men in green light.
"Identity confirmed: Astropath Guidos. Secondary authorization required."
Guilliman stepped forward, offering himself for the scan.
"Identity confirmed: Roboute Guilliman, Primarch of the XIII Legion, Regent of the Imperium, Lord of Ultramar. Gene verification in progress."
A beam swept across their bodies.
"Gene scan complete. Password verification required."
A light-cone field enveloped Guilliman, rendering all sound beyond it inaudible.
Kaul had entrusted the final code to Guidos alone. Not even Guilliman knew the full sequence. This safeguard was a contingency, preventing potential compromise through memory extraction or psychic intrusion.
As Kaul once warned: "Never underestimate Chaos. They're far more cunning than we give them credit for."
Guidos spoke the hidden code. The sound cone dissolved.
He raised a sound-shield, giving Guilliman privacy.
Guilliman completed his part of the code.
"Dark code verified. Main system activation commencing."
Panels on the wall slid downward. Behind them, ten reinforced glass cabinets were revealed, each filled with nutrient solution containing a severed human head.
Each head was connected to a network of cables, their necks encased in metal collars. The machines above flickered to life. Etched circuitry across the glass pulsed with a dull light, and the preserved faces began to twitch in discomfort.
"My lord," said Guidos softly.
"You may leave," Guilliman ordered with a wave.
Guidos bowed with the Skyhawk salute, drew his hood over his head, and vanished into the shadows.
Guilliman watched silently as the systems came online, one by one.
A metallic voice finally emerged, lifeless and resonant, like brass grinding against iron.
"Master Primarch."
"Cawl, report your progress," Guilliman commanded.
The voice came from one of Cawl's clones—or rather, a sub-personality. Cawl transformed data into code, transmitted it, and allowed the Glory of Macragge to reconstitute it into intelligible form. The clone then used the information to converse with Guilliman.
This type of neural-mimicking tech was borderline heretical in the eyes of the more dogmatic Tech-Priests of Mars. Without Guilliman's protection, Cawl would have been executed. If his inventions leaked, the Mechanicus would not hesitate to dismantle his mind and repurpose it as a servitor, using his consciousness for grotesque experiments.
Cawl's daring innovations had sparked deep enmity among the more conservative Magi. Their ideological clashes threatened civil war within the Adeptus Mechanicus, curbed only by the unity demanded by the Imperium's survival.
"The Great Sage's work is progressing. The Primaris Space Marine Project has entered a new phase. Four additional enhancements are underway: tendon coils, hymn-producing pituitary glands, the Belisa Furnace, and a new organ known as the Heart of Guilliman."
"The Heart of Guilliman?" Guilliman's brow furrowed.
"Yes. Inspired by your own genetic matrix, this new organ incorporates superhuman potential. The gene-engine, derived from your biology, will be the cornerstone. It reshapes the subject into a post-human ideal. More importantly, the Heart can be remotely deactivated, paralyzing any rebellious Primaris. This may prevent another Horus Heresy."
"The Mechanicus also recommends revising the implantation procedure. The Heart of Guilliman will be the first organ installed. This change will increase surgery success rates and allow for rapid mass production of new Space Marines."
Guilliman stood in silence.
"It's an audacious plan. Risky, perhaps, but it merits exploration. I'll authorize expanded clearance for your team."
He allowed himself a rare smile.
"Madness can sometimes lead to salvation."
And somewhere, across the stars, hope stirred once more in the crucible of mankind's darkest age.
Here is the revised version of Chapter 31 of your Warhammer 40K fanfiction. It's been edited for grammar, clarity, tone, and structure, while keeping the word count close to 1500.
Chapter 31 – Brand New Warrior 14
"Guilliman, thank you for your hard work," said the psyker.
The one who spoke was Guidos, chosen from among those psykers loyal to Guilliman and entrusted with maintaining the clone of the Archmagos Dominus Belisarius Cawl in the hidden depths of the Macragge's Glory.
This part of the vessel was so secret that even trusted commanders like Captain Sicarius were denied access without explicit authorization.
"It is the highest honor to serve the Lord of Ultramar," Guidos said respectfully, his pure white eyes gazing upward in reverence.
Guilliman nodded. "Your loyalty is appreciated. Let's begin. I need to review the message Cawl sent so I can maintain full situational awareness."
Guidos nodded and turned toward the shadowy corridor, leading the way.
As they walked deeper into the restricted section, the temperature rose. Hidden machinery thrummed in the walls, and a heavy psychic pressure pressed against Guilliman. It was stifling, but the Primarch endured it without complaint, following closely behind the astropath.
Eventually, they reached a massive door. Its structure was intricate, comprised of three staggered layers of tortoise-shell mesh, each a meter thick.
Guidos approached the access panel and opened the outer seal slightly. Guilliman stepped forward, submitting to the retina scan.
"Retina scan passed," came the voice of the machine spirit.
Additional systems emerged from the steel walls—mechanical arms and scanners whirred to life, testing Guilliman's physical, psychic, and spiritual state. Only once all parameters were confirmed did the final lock disengage.
They stepped inside.
The chamber beyond was utterly dark.
"Illumination," Guidos called.
The machinery responded, humming as overhead lights flickered on, casting a sterile white glow over the interior. The room's layout was now clear—ten sealed panels were mounted at eye level, with tightly bolted pipes snaking down from the ceiling.
"Cawl's psychic transmission was… peculiar," Guidos said. "It lacked the resonance of true mental communion. I suspect he used some sort of machine-assisted method to transmit it. I once believed such a thing impossible, but I must admit—he is a master of his craft."
Guilliman gave a slight shrug. "If I didn't have access to the Imperial database, I'd say Cawl is the most learned man alive."
Cawl had survived for over ten thousand years—truly lived, not merely endured. An unprecedented feat. All other known Human Perpetuals had vanished or died during the Horus Heresy. To Guilliman's knowledge, Cawl was the longest-lived human in the Imperium.
"His message is simple," Guidos continued. "Devoid of the usual warp corruption we see since the Cicatrix Maledictum opened. No psychic interference, no malice. A rare purity these days. That kind of clarity is valuable. The Rift threatens not just lives but the future of our species."
"That will change," Guilliman said firmly. "I swear it."
"I believe it, my Lord." Guidos stepped up to a massive machine and began the activation sequence.
"In the name of the Omnissiah, initiate protocol."
He leaned on his cane, speaking the pass-phrase.
With a groan, the steel walls shifted, followed by the clatter of internal mechanisms. Beams of light swept across them.
[Identity check: Astropath Guidos. Please provide secondary authentication.]
Guilliman stepped forward for his scan.
[Identity confirmed: Roboute Guilliman, Primarch of the XIII Legion, Lord of Ultramar, Regent of the Imperium.]
[Gene-identity scan initiating.]
A green beam swept across the pair, verifying their biometric and genetic signatures.
[Gene scan confirmed. Password authentication required.]
A soundproof energy field formed around Guilliman, blocking all outside noise. The second part of the code had been entrusted to Guidos alone. Not even Guilliman knew it.
A necessary precaution—if the Primarch's mind were ever breached, secrecy could be fatally compromised. Cawl had warned him: "Never underestimate Chaos. They are smarter than you think."
After Guidos murmured his code, the sound cone dissolved.
He then raised a sonic barrier to shield himself as Guilliman spoke his own phrase.
[Code sequence verified. Main system online.]
The steel panels in the chamber slid open one by one.
Behind each lay a glass chamber filled with nutrient fluid. Inside each floated a severed human head, metal sheaths embedded at the neck, cables and tubes running from the cranium into the ceiling's machinery.
The machines roared to life. Circuits etched into the glass pulsed with light, and the faces of the heads inside contorted in pain as they activated.
"My Lord," Guidos whispered.
"Leave us," Guilliman said with a wave.
Guidos saluted with a Skyhawk gesture, then pulled up his hood and retreated into the dark.
Guilliman stood alone in the chamber, watching as each system activated.
A grinding metallic voice echoed from the walls—emotionless and dry, like brass scraping stone.
"Lord Primarch."
"Cawl, what's your status?" Guilliman asked.
The voice belonged to one of Cawl's clones—a sub-routine body designed to convey messages converted from machine code to speech.
Cawl transmitted information using encoded technosorcery. Once received by Macragge's Glory, the clone would interpret it for Guilliman. This technology danced dangerously close to forbidden lore.
And yet, Guilliman trusted Cawl.
Without his protection, the Archmagos would have long ago been excommunicated, lobotomized, and repurposed as a servitor. His radical innovations were deeply opposed by more conservative elements of the Mechanicus. Had it not been for the stability of the Imperium, their ideological dispute might have erupted into a full-blown civil war in the name of the Omnissiah.
"The Fabricator-General reports successful progress. New technologies have been deployed. The Primaris Space Marine Project is expanding. There are four new augmentations—tendon coils, the Hymnal Gland, the Belisarian Furnace, and the transformation known as Guilliman's Heart."
Guilliman raised an eyebrow. "Guilliman's Heart?"
"Yes. Inspired by your genetic design, this new organ merges superhuman physiology with gene-engineered adaptability. It will allow for greater resilience, better integration of implants—and more importantly, it includes a remote shutdown function."
Guilliman's expression hardened.
"It will grant us a safeguard against future betrayals," the clone continued. "Should any Primaris Space Marine turn against the Imperium, we can disable them instantly. The Mechanicus proposes to make Guilliman's Heart the first implant in the surgical sequence. This will improve survival rates and streamline the mass production of Primaris troops."
The Primarch folded his arms. "The idea is bold… perhaps dangerous—but worth pursuing. I'll authorize increased clearance for your work."
Even as he said it, a half-smile formed on his lips. Cawl's ambition was dangerous, yes—but it was also necessary.
Guilliman could not afford fear or hesitation. Not when the Imperium stood on the brink.