"A control rod!? No no no nonono that won't work! That's for fission reactions. Putting something that absorbs neutrons in a fusion reactor would just disrupt the cohesion of the plasma! It might make it explode!"

Kanako laughed heartily as Renko stood up, clutching her hat with a panicked expression on her face. "You're still mired in the logic of Outside world science. No one here in Gensokyo knows that, most especially not Okuu. I told her that it was a control rod, and that it would help her to control the power of the divine fire. If that's what she believes, that's what it will do. It's all a matter of perception, Renko."

"That doesn't make any sense! How can you be sure things will work that way? Whether we call it nuclear fusion or divine fire, that's still a level of power you can't just play around with, isn't it?"

I let out a cautious breath and looked up at Renko. "Maybe it's like the placebo effect," I posited. "Even in the Outside world, and under the auspices of rational science, multiple studies have shown that the belief that something is beneficial has a measurable impact on a person's wellbeing. That impact persists even if the person taking the placebo is informed that's what their pill is. If Okuu perceives herself as under control, maybe that's all that matters."

"That was exactly my thinking as well. Once the hell raven has become comfortable with manipulating her divine fire, we'll harness her abilities to create limitless, clean power, with no radioactive waste to dispose of and no associated risks. Fusion is the power of the sun, after all, the ultimate sort of green, solar energy. Suwako is watching over her right now, guiding her toward that bright future."

Renko shook her head in dismay, her fingers still twined in her hair. "So we're supposed to believe it's all under control now. Lady Yasaka, do you know about the geyser that's erupted near the Hakurei shrine?"

"I've heard it mentioned, and seen the plume. Are you concerned that that is a result of Yatagarasu's influence?"

"I'm more concerned about the fact that there are earth spirits coming up out of it. Had you heard about that part too?"

"I had, but I don't see how it's any of our concern. The Hakurei miko should be able to exterminate such threats easily enough, and once we've successfully harnessed the power of fusion, the heat driving that geyser will be put to use elsewhere. The spring should dry up then, and we can patch any breach that may have allowed a leak. That's a problem with the outdated infrastructure of the abandoned Hell down there, as I see it, not anything related to our project."

"I take it you never bothered talking to that kasha, Orin then. Suwako may be watching over Okuu and guiding her to gain more control over the power of fusion, but does she have any idea what Okuu is planning to do with that power? Do you, for that matter?"

"I'm not sure what you mean. It's simply the power to create divine fire. She already lives in a subterranean cavern purpose-built to withstand tremendous heat. What could she be planning? What would it matter anyway? Once she's mastered her control, and we've built a properly sized boiler and turbine setup, we'll put her to work."

Renko stared at Kanako with a look of utter disbelief and ran her hand down her face, groaning. She released a slow, centering breath, then sat back down at the table. Pausing for just a moment to gather her thoughts, she locked eyes with the goddess across from her. "Lady Yasaka. If I told you that your plot was in danger of instigating a genocidal war of destruction on all of Gensokyo, would you believe me?"

Kanako leaned back at that question, blinking in surprise.

-.-.-.-.-

"...Well. That's quite a story." Kanako said, crossing her arms and groaning. Renko had spent the last hour explaining everything we had found during our two-day stay in the Underworld. "We had expected that the hell raven might go a bit out of control at first, but we thought having the oni so nearby would help keep her in check. We never expected she would have designs for the surface." She let out a long sigh as she tapped her head with her fist.

"So the kasha released the earth spirits as an SOS to the surface. I wouldn't ever have imagined there was a message behind that."

"Yes. That SOS reached the magician from the Scarlet Devil Mansion and has since spread to Reimu, Marisa and Yukari already. I expect Reimu and Marisa will be heading to the Underworld today or tomorrow."

"Well that's just fine. No matter what the Hakurei miko happens to do down there, our hell raven will retain the power of Yatagarasu, and from everything I've heard about her, she doesn't make a habit of actually exterminating youkai. If she manages to tame our reactor for us, then that's just a bonus.

"If Reimu does that though, she's going to find out about your plan. Once that happens you'll not only have her to deal with, but the youkai sage as well. You've knowingly broken the non-interference pact between the surface and the Underworld, Lady Yasaka."

"Reimu's complaints I can handle. As for the treaty, I was under the impression that it was signed by the youkai of the surface and the youkai of the depths. As a goddess, I am neither of those things."

"You're being very optimistic if you're counting on the youkai sage agreeing with your interpretation of the law."

"I'm certain there's room for negotiation. In a worst-case scenario we can be party to the negotiation of a new agreement between the surface and the Underworld. I'm no stranger to playing politics with various factions."

"So then the official position of the Moriya shrine is that you will do nothing about this Incident? You're content to just let the pieces fall where they may?" Renko asked, leaning back from the table and crossing her arms in frustration.

"You sound almost reproachful, Renko. Were you perhaps hired by that kasha to extract some token of contrition from me? Did you promise to get me to remove Yatagarasu's power from that raven or something?" The condescending smile on Kanako's face seemed almost piteous.

"Well, nothing that specific, but yes, I was hired by Orin. She's worried that Okuu will go out of control and cause trouble for her master, losing them both their positions in the Underworld."

Kanako nodded, still smiling, then rested her cheekbone on her upraised palm as she propped an elbow on the table. "Well, her concern for her friend is touching, but that kasha is worrying unnecessarily. We may not have known what that hell raven was planning, but she was never a threat. If she had tried to come to the surface, Suwako or myself would have stopped her. We take turns watching over her, and her power is not so great that we couldn't stop her if the need arose. Did you really think that I would knowingly create something so dangerous even I couldn't control it? I worry that our close association through Sanae has robbed you of a proper sense of awe for the might of a god."

"Well, that's a relief for me to hear, but Orin wasn't really concerned about that. She was more worried that Okuu might get hurt in the process or that one or both of them might lose their master's favor as a result."

"When you say 'master' there, you're referring to the satori who owns the mansion straddling the Hell of Blazing Fires, are you not? If so, I don't think you or the kasha will need to worry about her either."

Renko reacted to that with a look of surprise. "Eh? Why not? Have you already met Satori, Lady Yasaka?"

Kanako grinned. "Of course I have. My plans would involve increasing and regulating the temperature of the Hell of Blazing Fires. Of course I had to speak to the landlord first to arrange that."

"So then... Satori already knows about Yatagarasu? She was alright with your plan to feed the eye to Okuu?"

"Of course! What sort of villain do you take me for, Renko? Who would go around feeding strange things to other people's pets without permission?"

At that Renko could only stare across the table dumbfounded. "Well wait, in that case... then you would have to have... but then... arrrgh!" Renko groaned and slumped onto the table.

"What's the matter?" I asked, poking Renko's cheek with a finger as Kanako looked on with concern.

"It's nothing serious, I suppose." Renko said with a sigh, still laying limply on the table. "I'm just going to have to re-think this whole Incident from the beginning is all. Just when I thought I had everything figured out."