Editing Order of the Obsidian Mirror (section)

===Subject H===
Sister Yketrina managed to leave the cell and seal the door behind her before her shock overtook her and she sunk to the floor, incredulous and, though she’d never admit it, terrified.

From when they’d captured Subject H, she’d known that they were gazing into the depths, but she’d fallen into the obsidian pool of unwanted knowledge.

She’d been part of the Divisio Hydra operation that had captured Subject H, remembered the elation. It had been the first successful operation in the three centuries of attempts and the particular mission had taken years and involved hundreds of agents, infiltrators, false double agents, and analysts. The only other operation of similar difficulty was the on-going Operation Lion, but that was only because the former 1st Legion was so guarded and powerful. Fighting the Hydra, on the other hand, was layer upon layer of subterfuge, and even then the enemy usually was able to commit suicide before they could be questioned.

It had taken months of work to get anything out of him but ‘I am Alpharius’, new techniques adapted from interrogating the cultists to get details of the cell. But even then, she couldn’t shake the feeling that something was being held back, so onwards Yketrina pushed. She convinced him that 2 and 2 was 5, that there were five lights on the ceiling. She began getting bits of personal life, childhood memories, stories of operations long past in a stream of babbling from the nearly broken rogue astartes, but still there was something Subject H was hiding.

It had taken a while to find compounds that would interfere with the astartes nervous system, but they’d finally done it. At first she’d been afraid that they’d not work, so slowly did they take effect.
Then came the wild sounds of hallucination and then did she begin the interrogation. It was slow going, but the truthseer acknowledged that boundary was gone.
She wasn’t sure what she’d expected, but it had certainly not been this:

“It was for The Emperor, it has always been for The Emperor.”