The journey back from the Sanctum Imperialis was a funeral procession for the Imperium's certainty. The silence was heavier than any battle cry. Guilliman walked at the Monarch's side, the space between them a chasm of redefined power. His god, the ultimate piece in his game, had been proven a captive king. The Custodes who escorted them were no longer wardens; their vigilance was now tinged with superstitious fear.
They returned to the Spire of Unblinking Duty. The opulent chamber, once a gilded cage, now felt like a neutral embassy. The pretense of captivity had evaporated.
Guilliman dismissed the Custodes, leaving only Shield-Captain Valerian by the door.
It was the Monarch who broke the silence. "I have seen the heart of your Imperium, Regent. I have seen your dying god. I understand the nature of your struggle now. A perpetual, galaxy-spanning war to maintain a fragile reality, all powered by the focused suffering of a single being." He paused. "And I understand that you cannot help me."
Guilliman's gaze did not waver. "And what is it you have concluded from this... understanding?"
"That my passive observation is over," the Monarch stated. "I have cooperated with your terms. I allowed myself to be housed, watched, and tested. Your test has failed. The terms of my presence on Terra have now changed."
His five knights stepped forward from the shadows. "My goal remains the same: to find a way to return to my home. But I will no longer wait for you to provide the answers. Your Imperium is a library of forgotten science and forbidden history. I intend to read its most restricted sections."
The Primarch's expression tightened. "What you ask is impossible. I cannot grant you unrestricted access."
"You are not granting me anything, Regent," Jin-Woo replied, his tone leaving no room for negotiation. "I am informing you of my intentions. You cannot stop me from walking through the walls of your deepest vaults. The only question is whether you will be an obstacle or an asset."
It was an ultimatum. Guilliman, the master of a million worlds, was being dictated to in his own palace. To refuse was to declare a war he knew he would lose. To accept was to unleash an unknown power upon the most volatile secrets of his age. He chose the only path a true pragmatist could.
"Your methods are… invasive," he said carefully. "If you are to proceed, it will not be as a thief in the dark." He straightened. "I will grant you access to the archives of Mars. The Fabricator-General will be… persuaded… to cooperate. But you will not go alone. A Shield-Host of the Custodes, led by Captain Valerian, will accompany you. Not as wardens. As observers."
It was a masterful attempt to reframe his surrender as a joint enterprise. It made no difference.
"Your observers are acceptable," the Monarch conceded.
His objective was now clear. The minds of the Ultramarines had contained whispers of the Mechanicus's darkest secrets: vaults containing 'heretical' xenos technology, studies into the nature of reality, and perhaps, the keys to navigating the dimensions between this universe and his own.
He issued a silent command to his First Knight, and through him, to the acting captain of his vessel in orbit. Prepare the Spear of Judgement. Set a course for Mars.
The game had changed. He had stared into the screaming heart of this universe and found it wanting. Now, he would begin to dissect its body, searching for the path home.
Guilliman watched him, the weight of his desperate bargain settling upon his shoulders. He had just pointed a living key, forged from the principles of death and silence, at the most complex, volatile, and jealously guarded lock in his entire empire. He could only pray that when the door was opened, it wouldn't bring the whole house down.