"So, Lady Yasaka's aim seems to be set up a geothermal power station or something of that nature. The extra heat down in the remnants of the Hell of Blazing Fires heats water, which boils to form a geyser and the resulting steam can be used to drive a turbine. If they've managed to find a geyser downstream of that lake on the mountain, she could even set it up to be a closed loop system that regularly refills itself. It wouldn't be able to generate continuous power, but it would be enough to charge devices with batteries intermittently and still be a huge step forward, technologically speaking, for Gensokyo." Renko said, nodding at her own deductions.

"That seems like a direct contradiction of the non-interference treaty between the surface and the Underworld. Do you think Lady Yasaka doesn't know about that treaty? She's lucky that she dug down to the Hell of Blazing Fires directly and not into the cave containing the city. Since almost no one can go into the sea of flames, word hasn't really gotten out yet."

"Indeed, she's very lucky, Merry. So lucky that I suspect it wasn't luck at all. It's entirely possible that she knew about the treaty and decided to ignore it. Digging down somewhere where she wouldn't be discovered could well be intentional."

"I didn't want to say that, but you may well be right. If she thought the rules were pointless or outdated, I can't see her obeying them." I let out a sigh and tilted my head back as Renko groaned and tucked her chin to her chest, arms crossed in front of her. "Hey Renko, doesn't that mean that our whole trip down here and the half-dozen or so times we've nearly died just today were all for nothing? We could have just asked Sanae about all of this up on the surface or maybe even had the goddesses give us a tour of their power plant."

"Wait a minute!" Orin said, her shoulders and the hackles of her back rising as her claws gripped the leather of the stool. "Are you telling me you're friends of this goddess, sisters? I thought you were going to help me!"

"No need for alarm," Renko said hurriedly, showing her palms again. "We're well acquainted with Lady Yasaka, but we're not her supporters and we certainly didn't know she was doing something like this. My partner and I are simply figuring out the course of events and discerning her motivations so that we can figure out how to get her to fix this problem on your behalf."

Orin glared and Renko with eyes narrowed to slits, lips pursed in suspicion. "Really?"

"I swear it. If you doubt my words then go ask miss Satori to read my mind and confirm it."

"You know I can't do that!" she said with a frustrated sigh, looking away and releasing her white-knuckled grip on the stool.

"This may well work out to our advantage. If the news is coming from us, we might be able to reason with Lady Yasaka. With any luck, we can simply contact her and explain that your friend is becoming unstable due to the influence of Yatagarasu and thinking of trying to set the surface world ablaze. If we do that, I'm sure she'd agree that the best course of action would be to remove Yatagarasu's power from Okuu and rethink her plan for now. Just leave this situation to Renko Usami, ace negotiator. I'll find a solution that leaves all parties happy."

"I thought you said you were a detective, sister?"

"I'm a great detective and an ace negotiator. Both require a logical mind and a gift for storytelling and persuasive speech, two of my specialties."

Orin glared at her skeptically, seeming to grow more suspicious by the moment.

"Look, I swear I'm on your side here. Our interests even align. Even if I were to act selfishly, what I would want most right now is to understand how an earthly god like Lady Yasaka was able to give the power of another god, especially a messenger of the chief god of the heavens like Yatagarasu to your friend Okuu. The easiest way to examine that would be to remove that power from her, which just so happens to solve your problem rather cleanly too, doesn't it? I'm an altruist, just trying to help out those in need."

"I think you're just an egocentric who's addicted to danger and sticking your nose in other people's problems, sister. I've carted away a lot of people like you over the years and they always tend to die young," She said, still eyeing Renko suspiciously, the cat ears on top of her head twitching. I had to cover my mouth to keep from laughing at her blunt, but accurate analysis. "Still, I believe you when you say you're curious about it, so I think we may as well give your plan a shot. If that Yatagarasu can be removed from Okuu, that would be perfect. Better than having the miko from the surface come and beat her up. I don't think I can just leave everything in your hands, but let's at least give your idea a try."

Renko snapped her fingers and grinned. "Good enough for me. The Hifuu Detective Agency is on the case. Merry, lets head back to the surface and go talk to Lady Yasaka!"

I sighed and ran a hand down my face. "What a lovely idea, Renko, I just see one issue."

"What's that?"

"How are we going to get back to the surface?"

She stared at me in silence.

I stared right back.

"Merry, could you maybe try to open a gap and..."

"No, Renko, it doesn't work that way. We're both just regular humans. We can't fly and we must be at least a thousand meters below the surface. We don't have Sanae here to carry us and no one from down here would want to risk violating the terms of the treaty by helping us up. Most of them would rather just eat us. I doubt there's a kilometer long staircase leading up either."

"Well how about it Orin, you said you've been to the surface before, could you bring us up?"

"No way, sister. I have to be real sneaky when going up to the surface and that hashihime guards the bridge nowadays. Besides I don't want to leave Okuu alone right now. I could take you to the hole that the goddess dug, but it's at the bottom of the sea of flames."

"We'd be burned to death, wouldn't we?"

"Probably. And that's only if Okuu doesn't notice you down there and vaporize you first. Maybe your spirits would be able to ascend up the shaft and talk to the goddess though. I'm willing to give it a shot, sisters!"

"Don't forget that you also promised to find miss Satori's sister and bring her back here, Renko," I interjected, hoping to change the topic.

"Ah, that's right, it's a busy time for our detective agency. Given that I can't be seen by Satori until we've solved this case for Orin here though, we'll have to deal with her problem first. That means our first order of business is to find a way out of this palace without being seen."

"Oh, no problem there, I know a route where she never comes," Orin volunteered.

"Alright, that's handy. Okay then. We'll have to look for Koishi later, after we've dealt with the matter of our current case. Satori didn't exactly give us a timeline, but we'll definitely have to keep Yamame waiting. With any luck she'll get bored and give up on eating us." Renko walked to the door and grabbed her hat and coat. Putting them on, she turned to me. "Once we're out though, you and I will need to find a way to get through the city and back up to the surface in one piece, Merry."

"Well we could always just stay here and wait. Patchouli will probably figure out what happened to us and even if she won't come down, I expect Reimu and Marisa will, eventually."

"That'll take days, Merry! Aside from how slow Reimu is to react to Incidents normally, she'll be even slower to investigate if her only indication that something is wrong is the word of a youkai. Besides, if those two come down here, there's sure to be a big ruckus and a lot of fights. Wouldn't it be better if we could resolve this issue quietly, without the need for all of that? If we wait for them we won't be involved at all, Reimu will just beat up everyone with any connection to the Incident and give us a lecture while flying us home. No, we need to find a different way up."

"Well, Yamame and Kisume seem to have no trouble getting past the hashihime guarding the bridge out of town, but I don't think we can trust either of them to let us go. We could ask captain Murasa if we could get to her. She even wants to go to the surface, but we'd have to figure out a way to get her whole ship out with her. Orin, you were mentioning you had a way to get out of the palace without being seen. Where exactly does that come out?"

"It's an underground maintenance tunnel I use to carry fuel to the Hell of Blazing Fires. One end of it goes to the sea of flames, but it has other exits all over the city. I can smuggle you guys out easily enough, just be sure not to touch anything in my cart or look under the sheets. Unless you want a few of these friendly fellas following you around that is," she said, gesturing to one of the odd bluish fireballs that continued to float around her. "They tend to get real attached to living folks."

Saying that, Orin walked to the door and poked her head out into the hallway. After scanning around for a moment, she waved us on and directed us a short distance to a small closet. Sneaking ahead of us, she opened a trapdoor in the floor and lead us down a ladder into a dark passage. I climbed after her with Renko following behind me. Once the trapdoor closed above is it was pitch black in the tunnel for a moment. Then, Orin reached the bottom of the ladder and held out her hand. Several of the fireballs swarmed into her palm, glowing brighter and illuminating a long horizontal shaft with their harsh blue glow. Along the walls of the passage were several simple wooden wheelbarrows, each covered with a sheet. It was difficult to tell with the dim light and deep shadows that the blue flame gave off, but I thought I saw a hand protruding from under the cover of one. I pointedly looked away.

"Thanks for the light, Orin," Renko said as she came off of the ladder. "Our eyes probably aren't as good as a cat's. Are those vengeful spirits that you're holding?"

"Yep!" she said with a smile that might have been cheery, but looked positively unnerving when lit from below by the blue flames that glinted off of her fangs. "I can talk to vengeful spirits, and command them too. That's why I have this job."

"A vengeful spirit is just the soul of someone who died and was sent to Hell, right?" Renko asked as we began to walk along the passage, following Orin's lead.

"Well, they're here because they're vengeful spirits, not the other way around, nya? Souls too steeped in hatred and bitterness to reincarnate until all of their malice has burned away and their karmic debt is paid off end up here. Suffering in one of the hells is supposed to help purify them, but when they shut down operations here, all of those souls got left behind for me to play with. Every now and again one of 'em gets reincarnated and I loose one of my toys, but there's always plenty more. I don't know if they get born again as oni or demons or if they get taken to the Netherworld or what though. I'm just the cleanup crew for the meat. These spirits are just kind of a perk."

"How did so many spirits get left behind? Isn't the whole point of the hells to keep punishing those condemned there until they can reincarnate?"

"Well yeah, but working off a lifetime of sin can take a really long time. Maybe forever, especially if the souls don't learn from their torture and just become more full of hate. Those sort are a pain for most people to handle, as they tend to possess anyone who tries. The Ministry was trying to streamline things, so rather than figure out a way to move all of the spirits left down here, they just sealed them away to be forgotten. They would have been too, if the oni hadn't eventually come down here."

"So even the Divine Ministry of Right and Wrong has to deal with staffing problems and cutbacks, eh? That gives a new meaning to the phrase 'bureaucratic hell.'"

"If you ask me, the Yama are as much prisoners as any of the sinners they condemn. They're both bound to suffer endless lifetimes of torment, one's just the exciting kind of torture and one's the boring kind. Leaving this Underworld behind makes sense though, its all twisty and dark. It must have been a pain to manage back in the day."

"Maybe, but leaving a whole city and all of these dangerous facilities behind seems reckless, even if you don't take into account all the vengeful spirits. I mean, you guys were able to restart the Hell of Blazing Fires, and the Lake of Blood is down here too, and seems to still be quite hellish."

"Well, I don't think they thought anyone was going to move down here. It was just us animals and the spirits back then. I don't think anyone on the surface even knew this place was here."

"I see. In that case, why didn't the Ministry take you along when they moved Hell? You seem uniquely suited to this sort of work, and I imagine good employees are hard to come by."

"Oh, I don't work for the Ministry. I just live here. Miss Satori does, but I just help her out."

"Is that so? Okuu is the same way, I assume? What exactly is the relationship that the two of you have with miss Satori that you're willing to go to such lengths for her?"

"Miss Satori? Hmmm, well, she's really nice... and she taught me an' Okuu how to talk and wear clothes and cook food and stuff..."

Their conversation continued, but I was startled into losing track of it. I had been following along behind them in the gloom of the tunnels, listening to their words and the echo of our footsteps on stone when we had walked right by Koishi, standing in the intersection between two perpendicular paths. In the way that seemed typical for her, my eyes had slid right over her at first, and it was only after we passed her by that my mind realized I had just seen her smiling face looming out of the darkness, cast in shades of eerie blue. When I put that together I jumped slightly and gasped in surprise.

Renko turned to face me. "What's wrong, Merry? You need the toilet again?"

"Why do you always assume that? No, I just saw Koishi."

"Really? Heeey Koiiiishiii! Where arrreee youuu?" Renko cupped her hands to her mouth and shouted into the darkness, twisting her head about as she did. I flinched as her voice echoed off of the walls.

I looked back to the intersection where I had seen Koishi, but she was gone. I couldn't blame her, I was tempted to run away from a racket like that myself. The path was a T-junction though, she could only have gone one way.

"Hey sister, you can see Koishi?" Orin asked. "How does that work?"

I ignored the question, which I couldn't have answered anyway and peered around the corner. With Orin and her flame ahead of me, I couldn't see far, but I heard the sound of footsteps receding, clear now that the three of us were all standing still.

"She went this way, I think she may be trying to guide us again."

"Well, everywhere she's lead us so far has been interesting. I wonder where we'll end up next?" I could see the contours of Renko's troublesome grin cast in harsh relief by the flickering of the blue flame as she turned to walk down the branching passage.

I reached out and grabbed the sleeve of her coat. "Hold on, Renko. Wait here for a moment."

"Eh? Why?"

"Every time you've gotten close to her she runs away. I think maybe if I go to her alone she'll talk to me."

"Huh? Why do all the most mysterious youkai hate me? Am I really that bad, Merry? Is she even really there, or are you just making up excuses to leave me behind?"

"Come on, Renko, you know it's not like that. I'd like to try pursuing her alone for a bit though. Can you two wait for me here?"

"Hey, don't ignore me, sister! Tell me how you're able to see miss Koishi! No one's ever able to find her."

"Like I told you, when you hire the Hifuu Detective Agency you get two for the price of one, Orin. Merry's eyes can find all sorts of things."

Orin frowned and looked skeptically at the both of us, then sighed. "Alright, we'll wait, but Koishi can be really unpredictable. Don't blame me if you get killed chasing her."

"Hey, Orin, come on. Merry's being very brave, volunteering to go into a dark and mysterious passage alone with an unpredictable youkai. Don't go and ruin her resolve."

"Alright then. Good luck, sister. Dibs on your corpse if you don't make it though. Oh, here, this will probably help." Orin raised her hand and pointed one sharp-nailed finger at me. One of the vengeful spirits swarming in the palm of her other hand streaked over toward me and began floating in a slow orbit around me, giving off a dimmer version of the pale blue glow in her palm.

"Did you just tell a vengeful spirit to haunt me?"

"Just for a little light company. It won't try to possess you. Not if it knows what's good for it!" She said, shaking a tiny fist at the floating ball of cold fire. The spirit seemed to tremble slightly, wavering in the air over my shoulder and pulsing its blue light. I tried not to think about the possibility of being possessed or being murdered by the unpredictable whims of a nearly invisible youkai, for that matter, and instead concentrated on willing my knees to stop trembling as I turned and made my way down the passage, toward the point where I had last seen the figure of the vanishing girl.