A flaw of the Daemon Core had already become apparent, emergent from its overwhelming firepower: Krahe didn't know how to get souldregs out of a nuclear shadow. Being a problem that she could only try to avoid moving forward, she left the scene as it was. Undisturbed. Her chest briefly split open down the middle as Barzai, now a formless mass of smouldering smoke, returned into the confines of her soul.
She returned to the lab, and there read through Sorayah's notes. Much of the material pertained to translations of the code used in her source texts, as well as to attempts at improving the ritual. Clinical descriptions, one after another, described the macabre failures of her efforts. After four subjects that died after only partial transmutation, Sorayah had given up and returned to the original method.
Mentions of a particular item stood out: The locked book. That was how it was referred to, as it had no external identifying markings besides the fact it was locked. Sorayah seemed to be completely stumped by what it was or how to open it, describing several unlocking experiments that had led her to believe somehow exposing it to anathema could be the key, but that was as far as she had gotten. From these notes, Krahe also learned that the book had been found in the same place as the hexagonal voidkey, but the specific place was referred to only as "The Dig Site.”
Krahe took care to minimize how much she disturbed Sorayah's work space, as she had not yet decided whether to keep the case of the Lost Sun Killer Myth to herself, whether to fully report it to the church, or to do something between these two extremes. One of the considerations in her mind, despite the wretchedness of it, was the potential usefulness of Human Charcoal. Sorayah's stock of the substance was already made, and even the church's disposal method involved burning it down to ash after a fashion - so if it turned out to be useful to her, simply handing it over would be wasteful and pointless.
In the course of going through Sorayah's home more thoroughly, things turned out to be inconveniently nuanced.
Everything that Krahe was able to find - from texts in the lab to those in the library - pertained to the process of turning someone into human charcoal and to artifacts that directly burned human charcoal as fuel. The problem came in with the mention of a substance described as "Black-flesh Jewel" in the older, more mystical texts. Meanwhile, newer fragments in Sorayah's possession referred to the same substance in more grounded terms: "Anthrocite" or "astral rock coal". Over the course of a few hours, Krahe arrived at two undeniable conclusions: Whomever invented and developed these occult arts had clearly gone much further than just human charcoal, and the Human Charcoal Letters didn't reveal the full scope and severity of the goings-on during the century they spoke of. To say she was surprised would have been a bold-faced lie.
Stolen content alert: this content belongs on Royal Road. Report any occurrences.
Krahe honestly wasn't sure what course of action to take, but she had the small comfort of knowing that Sorayah wasn't likely to have visitors any time soon - at least speaking on the time scale of weeks. With that in mind, Krahe took the keyring Sorayah had left inside the ritual chamber's doors, as well as the one with the house keys. After placing Sorayah's lantern, the locked book, and several samples of human charcoal into her Kenoma Sack, she left the place behind for now. The key, after closer inspection, was not entirely homogenous in shape - the side of it which would be inserted had a narrow hexagonal hole about a centimeter across and of an indeterminate depth.
After spending the rest of the day looking into the Human Charcoal Letters at the Temple of Records, she reconvened with Casus at the safehouse and, since she needed his assistance in this matter, let him know of what had transpired.
"As Mamon Knight Silberblut, I would say she met a fate rightly deserved... Though I would likely put it less politely. Out of the armor, however, I cannot help but feel she would have been more useful if she had been interrogated in an official setting," Casus remarked on the situation, drinking his coffee and reading a book as he always did - this time, he had borrowed Krahe's copy of De Re Theurgia. He turned his gaze up from the book in his hands, nodding towards the hexagonal voidkey standing upright on the coffee table. "You mentioned that you managed to coax her into giving over her voidkey and needed help identifying it, is that right?"
"I wouldn't say there was much convincing on my part, she tried to use it as bait to make me approach within range of her last-ditch theurgy attack... But yes, I do need it identified."
Unsurprisingly, Sorayah's voidkey had robust anti-appraisal enchantments. Casus managed to break them after trying for a few minutes, describing them as "fortress walls built to hide an ancient mausoleum".
"They're new. I would guess they were made by Sorayah herself or by someone on her behalf," he clarified afterwards. "Rather than being incorporated into the key's construction, they were merely layered around it. Moreover, there are traces of anathema- er, isotope suppression glyphs, never activated. Whatever radiation the key gives off, it is merely very close to anathema. Give me a moment..."
Casus got up, returning with an Oculon-branded device and a handful of bronze memslates. Its design language was the same as the eyebox Krahe had taken from the dead prospector, but it was thrice as large and far more complex. It very slightly resembled a 20th-century tape recorder in shape. It had sockets for four memslates, a more expansive keyboard, and a row of cable sockets on one side. A vial of thaumine sloshed around on the other side.
Casus popped in a pair of memslates and plugged a black cable into the device, nerve-like endings surging to life from the cable to complete the connection when brought near one of the sockets. With a hiss and the turn of a locking ring, the cable was connected. At its other end was a flat, key-like plug, and much like a voidkey, Casus inserted it into his temple.