Ma En left his bed, stripped off his pajamas and tossed them on the sofa, then walked into the bathroom and let the shower run hard.

July in Japan was stifling — the past few days had pushed to a high of thirty-five degrees by the weather station's measure, and that was only the official reading; stepping outside around noon, you genuinely started to wonder whether it hadn't crept to thirty-six or thirty-seven. Even in the morning, the water from the showerhead came out faintly warm.

Even so, it cleared his head considerably. He hadn't forgotten the dream — the dream about the past, about pain. Compared to the nightmares the Matchmaking God had sent, the dream that had woken sleeping memories of childhood was undeniably gentler; and yet it, too, had stirred something dormant inside him, a kind of spiritual pain — he wanted to call it that, then felt the word didn't quite fit. If he examined it honestly, that pain which had woven itself through his childhood had never left his life for a single moment.

He'd simply stopped actively summoning it. Just as an adult eating roasted sweet potatoes doesn't need to think back to how sweet potatoes tasted in childhood — some people will recall, and some people's minds won't go there at all.

With university as the dividing line, his pain had been cut into "before" and "after." He had instinctively avoided drawing too tight a connection between the two, because doing so made him feel as though nothing in him had ever changed — that his life had no variation. And even as that thought formed, he couldn't help but note: whatever he felt about it, the pain that had long ago become part of his life had truly not changed. Not ever.

No matter what shifts his personality had undergone, no matter how much his perception had expanded, no matter how much knowledge and experience he had accumulated — pain alone had remained constant. It was like a ligament binding past and present together, pressing a mark into genes, cells, muscles, nerves, and brain. His father and mother had told him this long ago, and he'd never wanted to dwell on it.

The more you look back, the clearer it becomes. Joy becomes sharp; so does pain.

—If not for this dream, he never would have consciously noticed something he'd long since taken for granted.

Ma En tilted his face up and let the water pressure work against his facial muscles. When he became aware of his own hands, they were already threading through his hair, pressing deep into his scalp. Too much force — a sharp pain, which made him sharper still.

Whether physical pain or spiritual, whether the kind that drifted in from memory or the kind that was currently lodged in his body — pain was like part of a net: lift one node and all the others moved.

It had struck him more than once: a little over a week ago, he'd been thinking about saying goodbye to his past self, telling himself he'd already "become a different person," and then later debating whether he should "go back to who he was" — both impulses struck him now as laughable, absurd, and the self who had entertained them as stupid and forgetful in equal measure.

His father had told him: "A person cannot discard their past self precisely because they cannot forget their wounds. In a lifetime, many wounds can only blur with the passage of time — they blur, but they remain. From the moment they were born, they were fated to follow a person's footsteps through every year of their life. People can never escape their grip. And so people can only ever be themselves."

—Whether "saying goodbye to the past" or "chasing the past back down" — both were foolish, laughable ideas.

Ma En felt ashamed of his own foolishness, and the shame was painful, and he knew clearly that he would carry this pain and not forget it. It was a lesson. He had never before had the opportunity to learn it.

—He wondered what his father's face would look like if he ever told him.

—Probably nothing but relief.

He knew: even on the day he could smile and tell the story as a joke, some corner of his heart would not be fully at peace. Old pain, like a small scar — poke at it and it still stings.

Ma En turned off the water, dried himself, wrapped the towel over his head, returned to the living room, and switched on the television.

The morning program was running another segment on the cracks and caves from the earthquake zone. Experts had been offering commentary for several days already, deploying technical vocabulary to dismantle each rumor in turn. Speculation about the cracks and caves had grown deafening and increasingly wild, with everyone holding a theory — even the theories that found agreement among themselves hadn't produced much benefit from that agreement. Across Japan, the earthquake and the cracks and the caves had already given birth to several new religious sects.

Human curiosity seemed inexhaustible, and yet it always seemed to stop just short of the truth. Sometimes Ma En thought most people didn't actually want to know the truth — they wanted to let their imagination run free, wanted to interpret and understand the world according to their own invented frameworks. Accurate or not didn't matter; what mattered was whether it felt right, because that was pleasant. Wasn't it? It was like the world rotating around yourself — like being the only one who had seen through to reality.

Whether it was public debate, or the proclamations of new religious groups, or the explanations offered by experts — Ma En had been following all of it. A great many people's attention had now been drawn to the earthquake, the cracks, and the caves; but these things were essentially all connected to whoever was behind the Room 4 ghost story. To put it simply: without knowing it, all these people had been caught in the gravitational pull of the Room 4 ghost story — even without knowing the story existed.

That was dangerous. The more people were drawn in, the more dangerous it became. Before that danger had fully erupted, nobody could be certain what would happen — but it made Ma En feel, more sharply each day, that the hidden terror was growing.

"...Professor XXX and his survey team have completed their preliminary analysis of the underground rock caverns and can confirm: these are definitively the traces of an intelligent species. As everyone knows, human beings are the only life on this planet that can truly be described as intelligent. Ha — great apes, dolphins? They do have intelligence, certainly, but what they have can't yet be called wisdom. The 'biological wisdom' mentioned in some textbooks? In the broad sense, yes — intellect and wisdom are closely linked — but the level of wisdom already evident in these caves is not something those animals could have achieved."

"I know, I know, many people right now believe this is an extraterrestrial legacy, or remnants of some prehistoric civilization — but I want to emphasize again, and I'll say it as many times as necessary: there are no extraterrestrials here, and there is no prehistoric civilization. These are traces left behind by Japan's early primitive humans during their period of activity. These caves weren't built by them — the caves already existed. They simply discovered them..."

"I'm very confident: a rich life was once lived here. The primitive humans who lived in this place weren't quite like what we're accustomed to imagining when we think of primitive humans. Look at these patterns, these cave paintings... What? Of course these are cave paintings — look here, there's clay as well. They made pots and stored them here. Do you see? This mark here is where a pot was set."

"...This earthquake along the coastal belt of Tokyo may rewrite Japan's recorded history by several thousand years."

"Look — what's this? Good lord, these marks, if we trace them out like so... everyone take a look — doesn't that look like a ritual? A primitive ritual — a group prostrating before some symbol, dancing, performing acts that are bloody and savage to us, and yet to them were profoundly sacred, of the utmost importance."

"...Based on our estimates, this section was a burial ground, this section was a living area, and this section was their garden or farm. Extraordinary — they actually lived underground."

"No, we have not yet found any remains that could serve as significant material evidence."

Ma En sat in silence on the sofa, cycling through a few channels. The content varied little — only the presentations grew progressively more alarming. The sudden force surging out of ordinary people felt restless, tinged with something almost frantic. In short: the currents were moving wrong.

"As a result of these cracks and caves, and the discoveries made by archaeological teams, more and more tourists have been flooding into the Tokyo area to witness this spectacle for themselves. I'll admit I was drawn to it as well — this is unquestionably a major archaeological discovery, with genuine positive implications for the study of human origins. But I still have to warn the public: without sufficient expertise, venturing inside is extremely dangerous."

"The government has sealed off the excavation sites, but people keep slipping through. Look at all this rubbish — are they camping in there?"

"According to private organization statistics, at least tens of thousands of people have now entered the caves..."

Ma En shifted his attention to the Bunkyo-only local channel, where a host was out on the street conducting interviews, asking passersby about the cracks in Sanchoumoku Park. The people she'd caught on camera were visibly excited; their clothing alone suggested they weren't types who sat still easily. All of them boasted, with varying degrees of pride, that they'd entered the cracks and caves, stringing together several "unbelievable"s to emphasize the experience. Through the camera lens — the flickering eyes, the pale faces, the hyperactive energy — they all looked like people who needed a good long rest.

Perhaps no one else would think much of it; but Ma En recognized that kind of exhausted-yet-feverish agitation, and it was not a normal state — he hoped his instinct was wrong, that these young people hadn't been caught up in whatever trap might be operating, but he couldn't convince himself.

There it was: every one of these people was representative of everyone who'd entered the caves — roughly eighty percent of those who claimed to have gone inside looked just like this, while the ones with healthy color in their faces were the ones who were actually lying.

Over these past several days, more and more people had been flowing into Bunkyo — the shift was legible from the street crowds and from snatches of conversation. The visitors had done good things for the local economy, but they'd also brought with them a deep unease. Not just ordinary unease. Something stranger.

A week was enough for many things to change. What made it frightening was not knowing exactly what had changed, or in what way.

For Ma En, none of it was going smoothly.

Nothing had been discovered. Matsuzaemon — the target he'd locked onto — seemed to have gone quiet, not a stir; and yet everything except Matsuzaemon himself had been growing stranger, with macro-level changes that were becoming difficult to measure. As for the things his allies had been trying to accomplish — none of it had advanced:

Hirota Masami had attempted to track down Professor Mitarai's whereabouts, but when she went to the television station and asked, they told her the professor had "gone out for fieldwork." Even with an address, there was no way to be sure where to find him before he returned.

Katsura Masakazu had tried repeatedly to broker a meeting between Ma En and Matsuzaemon, and had been turned away each time. Katsura-sensei was worried, but warned Ma En not to force his way in — that would cause a larger problem, and Ma En might end up as the criminal. Whether to meet Ma En was Matsuzaemon's decision alone. Katsura-sensei had also considered using a social occasion — a banquet of some kind — as an indirect way to bring Ma En into proximity; but Matsuzaemon had been keeping an exceptionally low profile lately. He'd taken leave from public duties, and at home was barely seen two days in three; nobody knew what was keeping him occupied.

When the apartment building completed its safety assessment and maintenance and reopened, the Room 3 neighbor friend was already gone. Half of Room 3 had been damaged in the fire the earthquake had started, and the building manager was concerned about the tenant; but even after filing a police report, it had done no good. Due to manpower shortages and various other reasons, the search had lasted only forty-eight hours.

Ma En had gone in and inspected Room 3. The neighbor friend had left nothing behind — no message, no hint. Beyond some plant residue, the only signs that someone had ever lived there were the remains of ordinary household things. Ma En could only speculate: the neighbor friend had perhaps discovered something, or made a new move, and simply had to leave. The most likely explanation — Matsuzaemon's attention had become a threat.

He hadn't forgotten: this neighbor friend had been so certain, so fixed on Matsuzaemon — just as they had locked onto Matsuzaemon, Matsuzaemon had simultaneously locked onto them. And so the neighbor friend had withdrawn, found new cover, waiting for the right moment. Ma En believed, without any doubt, that this person was alive, and would make contact on their own terms. He'd been waiting for it ever since.

One more thing had stayed with him.

When Ma En returned to the apartment, the building manager had mentioned it in passing: "The guest from Room 5 came by."

"...What were they like?" Ma En had asked immediately.

"No idea."

"No idea?"

"The landlord said so. That mysterious guest has permanently vacated Room 5."

"As I recall, Room 5 was sold outright?"

"Yes, the full deed has been handed back." The manager didn't seem particularly bothered. "I went to look this morning — it's just an empty room. Clean, though... Still, if someone buys a property and never actually lives there, it does seem like a waste."

"Does the landlord know who the guest of Room 5 was?"

"No idea — not really my business."

"Could you give me the landlord's contact number? I'm curious about who the Room 5 guest was."

"I can't do that — not planning to lose my job over it." The manager had said it warily, then offered a piece of advice: "Young people shouldn't let their curiosity run away with them. There's those cracks and caves everyone's talking about — don't go near those either. Nothing's gone wrong so far, but if something does, you'll be too late to regret it."

Afterward, Ma En had gone into Room 5. It was, as he'd expected, much the same as the brief glance he'd caught during the earthquake. No word described it better than "empty." No trace of a life lived, no sense of human presence — and yet the room was immaculate. He pressed a fingertip into the corner: not a speck of dust. Despite the earthquake, despite the fire, despite no cleaning crew having been dispatched, because there'd been no registered tenant — the room was this clean. As if something invisible and strange still lingered there.

Over the past week and a half, Ma En had inspected Room 5 many times. He'd rigged the lock so he could enter at will. He hadn't found a single lead.

The one thing that gave him any comfort: Asuka had sent word that she and her mother had gone to their old home in Kansai, where she planned to begin her manga work in earnest. Her father was still working at the ramen shop, though — Ma En visited every two or three days and talked with him for a while. Even if Asuka's father had no connection to any of this, his work put him in contact with a wide range of people and a steady stream of neighborhood news.

Every line of investigation had stalled at the same invisible point. Ma En kept sensing something — some formless presence he couldn't name — that seemed to be holding him back from going any further. Not yet.

He told himself it was an illusion. But he still had to stay clear-headed, absorb the pressure, keep the restlessness down. All he could do was wait for a new opening.

The pain of this waiting, he thought, was probably what had brought the dream of the past.

Pain is always interconnected.