After saying goodbye to Satori and being escorted to the door, we walked away from the palace, through the deserted plaza surrounding it. "So, Renko. We're trapped in a city full of monsters, thousands of meters beneath the surface, far from anyone who knows us, surrounded by things who want to eat us, with no way back and a mission to find a girl who's mostly invisible. What now?"

"Well, whatever we do, I'm going to be reliant on you for this one, Merry. I haven't seen this girl once yet, but Satori seemed pretty sure you weren't just seeing things. Maybe if you share your vision with me I could help you search, but that might get complicated."

"I'd have to cover your eyes to do it, so we'd only have one set of eyes looking either way. I don't think there's much point to trying."

"I suppose you're right. As much as I hate to admit it, this is a job that requires a top-of-the-line boundary detector. It's all yours, Merry. Good luck."

"I suppose that's fair. I've been relying on you for everything else down here. Still, I'm not sure where to begin..." I said, scanning around the plaza. "For all we know that girl might be back inside the palace rather than out here with us. It's her home, and she lead us here, right? Really our only hope for finding her is that she wants to be found. Assuming that I do actually find her, I don't know what I could do to convince her to go home. I might have unusual eyes, but beyond that I'm just a regular human."

"If you can get me close enough to talk to her, then you can let me worry about that. She's a youkai, but I'm sure she's still a reasonable person."

"I don't know if we can assume that in this case. What do you think Satori meant when she said that Koishi had 'placed herself in the realm of the unconscious? If she's not really conscious any more, can she be reasoned with? She kind of seemed to ignore everything I was saying to her, but she understood that I could see her. I wonder what exactly it would mean to only have a subconscious mind."

"To answer that, we'd need to be able to draw a clear line between where the conscious self ends and the subconscious begins. I don't think even you could do that, Merry. Both as a Relative Psychologist and as a boundary detector. It's too nebulous a line, and in a place where no one can see it, right?" She grumbled and fiddled with brim of her hat. "Since she's Satori's younger sister, I think it's safe to assume she's also a mind-reader. If she's become a subconscious youkai, maybe that means she can only read subconscious thoughts now though... Do you think either of them can do more than just read minds? Like maybe control them or implant ideas? Most youkai we've met have some special ability they've mastered in addition to their nature as whatever sort of creature they are. Aya's fast even for a tengu, for example, and Suika can do things I haven't seen Yuugi or any of the other oni do yet."

"If you're suggesting that Koishi might be able to the manipulate the subconscious thoughts of others, how would we ever even know? By definition anything she did there would be undetectable to the person she affected."

"Right, but not to anyone else. So let me know if I start acting out of character, I guess." Renko said, turning and walking with a purpose. "For now though, let's explore the grounds. It looked like there was more to this palace than just the house and a big empty square. I want to go around back, we can search while we talk."

Poking around a bit, she located a paved path leading toward a garden in the back of the palace. It was a statuary garden, with lots of beautifully carved marble basins and abstract geometric forms cast in white, black or pink stone and divided by low walls and interspersed with fluted columns. Stone troughs ran with trickles of cold, clear water, making for soothing background noise and a pleasant sense of calm in the dim, starless night of the caverns but a garden without any plant life seemed somehow desolate despite the care that had clearly gone into its layout. Renko called out as we walked, cupping her hands around her mouth and shouting "Koiiishiii~" into the empty night.

"Hey Renko, I noticed something else during that conversation with Satori. She was reading our minds and proceeding as if we were speaking to her, but she was still asking questions at certain points. Does that mean she can only read things if we're actively thinking about them?"

"That's a good catch, Merry. Though it's pretty hard to avoid even thinking about a topic when someone asks you about it if you were thinking of trying that. We can tell where her thought process is going through those questions though. I don't think she'd know what you had for dinner last night without asking you and getting you to think about it, for example, but if you had a stomach ache and were thinking about all the things you might have eaten to cause it, then she probably could."

"So then she can only read the conscious parts of our mind. That's supposed to be the smallest part of everything that goes on in our brains. The acts of recognition, categorization, comparison, co-ordination, storage and retrieval of memories and even most decision making is all subconscious. Most people couldn't tell you why they like a certain color or flavor, they just do, for reasons that are a mystery even to them."

"And Satori said she couldn't read her sister's mind. So Koishi must operate entirely below that level, wholly in the realm of the subconscious. Does that mean that even she doesn't know what she's going to do next?"

"Hmmm, you might be right. That's going to make her hard to find, if there's no predictability to her actions."

"Well, hold on Merry. We don't know that she'd be unpredictable, just that she wouldn't be able to predict it. If we could understand her motivations, we might be able to predict her actions even if she couldn't. I don't want to get too deep into a conversation about Relative Psychology or subjective epistemology right now but its a question again where the line between conscious or not sits. Could Koishi have a favorite food we could lure her out with? Or something she might be particularly afraid of? Would she even be capable of having preferences?"

"According to the precepts of Relative Psychology, she would. According to our model of cognition, the 'subjectivity' of an individual is comprised of a series of bindings between recognized concepts. That catalogue of connections is unique to each person and controls the way that their brain interprets stimuli. For example, in my mind the concept of 'Renko' is connected to the concepts of 'Hifuu Club' and 'Coworker' and 'The Noisy Girl Who's Always Getting Me Into Trouble.'"

"Oh come on, Merry, you can connect me to a better concepts than that. How about 'The Most Important Person In the World' or 'The Sexiest Person I Know?'"

"You're confusing your own mental catalogue with mine. The point I was getting at was that concepts are connected to eachother, and those connections form the basis of our judgements. I see you one way, but to one of our students, if they saw you the connection they would make would be 'math teacher' and to the youkai in the streets here, 'Renko' is more likely to be connected to concepts like 'tasty' or 'bony.' Actually, I agree with that last connection. Those connections are tied into recognition though, and evaluating them and deciding if we like something or not based on what concepts it's connected to is a subconscious process. That's why you might think someone looks shifty even if you've never met them before, or why you might have an idea of what someone looks like even if you've only ever read their writings or heard their voice. Everyone builds a different mental model of stimulus they perceive and concepts they recognize based on their internal catalogue of associations. So even if Koishi has no capacity for conscious thought at all, she'd still know what she did or didn't like."

"Ah, I see, then conversely the reason I can't see Koishi is because she doesn't, or maybe can't have any of those connections associated with her. My eyes might register her presence, but even if she were standing on a rooftop dressed like a clown and waving sparklers she'd just be another face in the crowd, right? But even if I can't recognize her as 'Koishi' could I still recognize her as 'A Little Girl With An Extra Eye'? I would think I would be able to notice that."

"You probably do, but the reason you think that would stand out is because you have meanings attached to concepts like 'Having Three Eyes' or 'Being a Little Girl In a City Full of Monsters.' A college student wouldn't be noticeable on a college campus, but if you saw one sitting on a slide at an elementary school's playground, you'd wonder what they were doing. Context gives things meaning, and Koishi seems to be impossible to contextualize. Even when I've seen her, it takes a lot of conscious effort after the fact to say 'no, wait, that was something I wanted to look at' to myself."

"That's weird to think about. I could've been seeing her all this time, but just failing to attach any meaning. Hmmm, I wonder if I could trick my brain into assigning meaning to things that are meaningless."

"I think you're already too good at that, Renko, given some of the theories you've come up with."

"Well, how are you able to see her, Merry? For that matter how are you able to see through Reisen's distortion or Nitori's optical camouflage? There's no boundaries involved in either of those, are there?"

"Not directly, but Reisen creates a border in front of herself then hides behind it. Nitori's camouflage does the same thing, but she wears it instead of projecting it. In both of those cases, I can't see the person behind the boundary when they're doing it, but I can see the boundary itself, so it's a dead giveaway. When Koishi spoke to me though, I could see her perfectly well, at least until I looked away. I'm not sure why, but it was definitely something different. Maybe I'm not seeing her with my boundary vision at all."

"If its not your boundary vision then it's even more mysterious. Why would you be able to see her when I can't? If it's not a matter of ability, is it a matter of perception? Does her ability not work on you?"

"It seems to me like it works less, I'd say. Though I couldn't guess why. It definitely still works though. It was hard for me to be sure she was there even when looking right at her. My brain was constantly giving me a 'wait, did I just see that?' sort of feeling, like when you see a jacket hanging on the wall out of the corner of your eye and think there's someone in the room with you."

"Very interesting, Merry. You're just full of mysteries. I wonder if your study of Relative Psychology has increased the strength of your unconscious mind, or if you've just become better at understanding these sorts of things from being here for a long time." Saying that, she took a step ahead of me and turned around, staring deep into my eyes. I stopped short and stared back at her. I found myself cringing away from the direct eye contact and blushing. Even after all of these years beside her, there was something about her gaze that sent a shock running through my nerves when she looked me in the eye. "You're becoming quite the detective yourself, Merry. This sounds like something right out of a Chesterton story."

"Oh, where context determines the meaning of an action you mean? You're right, but we don't have the strictures of English society of Chesterton's time to provide a set of background assumptions for the criminal to transgress here." There was more to that conversation, but if I were to record it here, it might spoil a true classic of detective fiction for you. If you ever get the opportunity, look for a copy of The Innocence of Father Brown. They have it at Suzunaan.

"Well, there you go then, Merry. Even if this case doesn't call for a boundary detector, it seems I'll still have to leave it to you. So you tell me this time: where do we go to see someone who can't be seen? In what context will we find the girl who defies contextualization?"

I sighed heavily. I was about to answer when a voice called out from behind us.

"Ooo! I know! Ask me!"

I turned around in surprise, and there she was, looking up at me from beneath the floppy brim of her sun hat. The girl with next to no presence. Koishi Komeiji.

"Ah! Were you there the whole time?"

"Yep, I've been right behind you all along!"

"Ergh, that's a little unsettling when you say it that way.

"Merry, who are you talking to?" Renko asked, peering around me to look where I was looking.

The second Renko looked her way, Koishi turned and ran, disappearing around the corner of a low wall.

"Wait! Don't go!" I called after her, but she had already vanished.

"Merry, was Koishi there?"

"Yes! She was right behind us the whole time!"

"Whoa, that sounds like the ending of some creepy urban legend or something. Which way did she go?"

"Umm, that way, I think. Around the corner."

We dashed after her, our boots crunching across the raked gravel as we left the paved path. Rounding the corner, I caught sight of her again, then immediately lost her once more. She seemed to be disappearing and reappearing at points further along a path lined by rows of stone columns, as if guiding us somewhere again. "Come on Renko, this way!"

It wasn't a long chase this time, though the path was winding again, darting in and out between rows of statues and on and off of paved paths. It wasn't much later that we reached what appeared to be our destination. In the rock garden behind the palace was an ornate caved stone building, or rather a mausoleum-like trio of walls and a roof, which surrounded a staircase that descend down, beneath the ground into blind darkness. Both Renko and I stopped short just before the stairs, pebbles of gravel skittering forward ahead of us and clicking as they tumbled down.

"Renko, those stairs lead down..."

"And below the Palace of the Earth Spirits is..."

She looked back at me. We said it at the same moment. "The Hell of Blazing Fires."

"Renko, this is a bad idea."

"We've come this far, Merry. We can't turn back now."

"We don't have Satori's permission to go down there."

"We have her permission to find her sister. We can't be blamed if that's where she went, right?"

We could have just gone back and told Satori her that this is where Koishi went. Going down the stairs was obviously a decision on our part. Moreover, it was likely that if Satori asked us about it, she would see that we stood here at the precipice and made the decision to go down of our own free will. But in the end, none of that mattered. I didn't want to be separated from Renko, especially not here, and especially not if she was going somewhere dangerous. Maybe I was becoming more like her. I can't deny that I was curious to see what might be down there as well. And so, I took hold of her hand and peered into the darkness. An unpleasantly warm and dry wind issued from below. I breathed it in, taking a deep breath to steel myself.

"Alright Renko, let's go."

"That's my Merry, nerves of steel. Let's do this! The Hifuu Club is going to Hell!"

And with that, we began our descent.