The Kamogawa Delta Cipher | Chapter 10: The Underground Waterway

The night at Nanzen-ji Temple said nothing.

Only water flows over the Suirokaku aqueduct.

Even when people make noise, tell lies, and hide secrets, the water flows at the same speed. As if it has known all of that for a thousand years.

Mio stood on the stone steps, staring at the photo on her smartphone.

《Returned》

The paper stuck to the wooden box.

But the shelf was empty.

If it had been returned, why was it empty?

In the first place, what had been inside?

Yuma peered at the screen from the side.

Who took this?

I don't know.

The woman from earlier?

Probably. But I can't say for sure.

The woman in the hat.

The red string.

Left-handed.

The person who drew the cipher on the Kamogawa River.

She had escaped.

The professor remained sitting where he was, refusing to lift his head.

Mio walked up to the professor.

Professor.

The professor did not respond.

What was inside this box?

A long silence.

Deep in the trees, a bird chirped once.

A mirror.

The professor said.

A mirror?

An old bronze mirror. It was believed to be from the Heian period.

The shelf is empty, even though it says it has been returned.

It is supposed to have been returned.

Yuma furrowed his brows.

Supposed to?

The professor slowly looked up.

It was an aged face.

The man who had been a researcher until just a moment ago suddenly looked like a criminal.

According to the records, it was returned to the temple after the war. But no one has ever seen the actual object.

Was it stolen?

Mio asked.

The professor did not answer.

That was his answer.

At that moment, Yuma's smartphone rang.

It was from Rui.

Where are you now?

Her voice was weak, but clear.

At Nanzen-ji.

Yuma replied.

Did you enter the storage vault?

Only the entrance. It looked like it might collapse, so I couldn't go any further in.

You must not go in.

Rui's voice grew stronger.

It has a dual structure.

Dual?

Mio took the smartphone.

What do you mean?

There is another passage deep inside the waterway. It was in my grandfather's documents. The storage vault on the surface is just a storehouse for show.

A chill ran down Mio's spine.

The real storage vault is somewhere else?

Yes. Probably, it's under the water.

Under the water.

From the beginning, that phrase had appeared many times.

The truth sleeps under the water.

It was not a metaphor.

Where is the entrance?

Mio asked.

Louis was silent for a moment.

On the right side of the sluice gate. There should be French initials carved into a part of the brick. C.E.

Canal Experimental.

That's right.

Mio looked at the professor.

The professor's complexion had changed.

It was the face of someone who knew.

Professor, you knew, didn't you?

The professor bit his lip.

It should not be opened.

Why not?

What is in there is not just cultural property.

It happened again.

The professor doles out the truth in small portions.

Because if he told the whole thing, he would collapse himself.

People are more fragile than buildings.

If just one lie supporting them is pulled out, they can no longer stand.

Mio looked at Yuma.

Yuma gave a small nod.

"You're going, aren't you?"

"Yeah."

"I won't stop you this time. But if it's too much, come back."

"I know."

"Really?"

"Maybe."

"You should say 'really' even if it's a lie."

Mio smiled a little.

With that smile, her feet began to move.

The three of them entered the iron door once again.

The professor followed them as well.

The air in the waterway felt colder than before.

The light from the flashlight was swallowed by the damp walls.

Water flowed in a thin stream at their feet.

The stone pavement was slippery.

Yuma walked ahead, and Mio followed.

The professor was at the very back.

They arrived in front of the sluice gate.

Through the gap that had opened earlier, a dark storage room was visible.

Inside, a few wooden crates remained.

Old cloth.

Broken pottery shards.

And empty shelves.

Mio shone her light on the right side of the sluice gate.

Bricks.

Moss.

White lime.

On a part of it, there was a faint engraving.

C.E.

"It really existed."

Yuma muttered.

Mio probes beneath the inscription.

A single brick was slightly loose.

She pushes it.

It does not move.

She pulls it.

That is not it.

Mio closes her eyes.

What would her father do?

If it is a mechanism for a waterway, it is not about force.

Water level.

Pressure.

Weight.

Yuma, close the sluice gate a little.

Huh?

Stop the water.

Yuma looks at the professor.

The professor remains silent.

Yuma moves the metal fitting of the sluice gate.

There is a creaking sound.

The flow weakens.

The sound of the waterway changed.

Mio pushed the brick once more.

This time, it sank in.

Click.

A small metallic sound echoed from deep within the wall.

A section of the floor opened slightly.

A dark hole.

It was a staircase.

"The entrance isn't below. It's above."

Rui's words came back to her.

It didn't mean the entrance was above the aqueduct.

Stop the water flowing from above, and open the entrance below.

That was what it meant.

Another piece of the puzzle fell into place.

The staircase was narrow.

It was damp.

There was no handrail.

Yuma went down first.

"Take it slow."

Mio followed as well.

The professor hesitated for a moment, but then came down.

The further down they went, the fainter the smell of water became.

In its place, there was the scent of dry wood and old paper.

Even though it was underground, the air there was stable.

It was as if time itself had stopped.

At the end of the stairs, there was a small room.

Red brick walls.

A stone floor.

A wooden shelf in the center.

On it, several boxes were lined up.

A piece of paper was stuck to one of the boxes.

《Unreturned》

Yuma gasped.

"So this is the real storage room."

Mio approached the shelf.

Box numbers.

Records.

Dates.

Things brought in during the war.

Things that were returned after the war.

Things that were not returned.

That distinction is written down meticulously.

It is not my father's handwriting.

It is older.

However, there was a new note next to it.

《2009 Confirmed A.A.》

It was my father's handwriting.

Mio's fingers tremble.

My father had come this far.

He saw the truth here.

And then he vanished.

Mio.

Yuma called out in a low voice.

There was a desk at the back of the room.

An old tape recorder.

A cassette tape.

On the label, my father's handwriting.

《Akito Investigation Record》

Mio held her breath.

She reached out her hand.

But the professor shouted.

"Don't touch it!"

His voice echoed through the basement.

Mio turned around.

The professor had turned pale.

"That is..."

"It belongs to my father, doesn't it?"

"No."

"You're lying."

Mio said quietly.

The professor's mouth snapped shut.

Mio picked up the cassette.

That was when it happened.

Footsteps came from the passage in the back.

Not just one person.

Multiple.

Yuma shone his light.

A man was standing in the darkness.

A black hat.

A low voice.

Mio intuited that this was the man from the blocked calls.

The man lowered his face as if to avoid the light.

Hand it over.

The voice was the same as on the phone.

You are the person who told me to stop, aren't you?

Mio said.

The man did not answer.

Do you know my father?

The man's shoulders moved slightly.

Hand it over.

No.

Yuma stepped in front of Mio.

Are you affiliated with the university?

The man took something out from his pocket.

It was not a knife.

It was an old set of keys.

This is a place that should be sealed off.

To hide what was stolen?

Mio said.

For the first time, I saw the man's eyes.

Anger.

No, fear.

"You don't know anything."

"I'm investigating because I don't know."

"If you find out, you'll end up just like your father."

The professor shouted.

"Stop it!"

The man looked at the professor.

"It's because you didn't stop it."

With those words, the air in the basement changed.

Mio looked at the professor.

The professor had his eyes cast down.

These two know each other.

And they know about my father's disappearance fifteen years ago.

Suddenly, there was a sound of water from the ceiling.

The flow is returning.

The sluice gate has moved.

Someone opened it from the outside.

Water seeps out from the cracks in the basement wall.

Yuma's face turns pale.

"This is bad. The water pressure is returning."

The man clicks his tongue.

Mio puts the cassette into her bag.

"We're leaving."

Yuma says.

"But"

"We're taking that and leaving now. That's how we win."

Mio nods.

The three of them head toward the stairs.

The man stands in their way.

But the professor grabs the man's arm.

"That's enough."

"It's not enough!"

"It's been fifteen years. I'm ending this now."

The professor's voice was trembling.

In that moment, Yuma pushes Mio forward.

They go up the stairs.

The sound of water grew louder.

The water had reached their feet.

It was cold.

It was heavy.

Perhaps the secrets created by people eventually return to the water.

When they emerged outside, the night breeze hit their faces.

Mio took a deep breath.

Yuma was also breathing heavily.

The professor came out a little later.

There was no sign of the man.

"Did he escape?"

Yuma said.

The professor shook his head.

"He knows another exit."

"Who is that person?"

The professor did not answer.

Mio held onto her bag.

Inside was her father's cassette.

For now, that was enough.

Water is flowing over the Suirokaku.

It is the same sound as before.

But to Mio, it sounded different.

She felt as if her father's voice was mixed into the depths of it.

After returning home, Mio played the old cassette with trembling hands.

Noise.

The sound of water.

And then, her father's voice.

《I am leaving a record. If Mio is listening to this, I am in a place from which I cannot return.》

Mio held her breath.

The tape continued.

《The cultural assets were not stolen. They were made to look as if they had been returned. But what really disappeared was not the objects.》

Yuma listened in silence beside her.

《What was erased were the names.》

The noise grew louder.

Deep within it, her father said clearly:

《There is a signature of a person who does not exist in the storehouse records. No, to be precise, it is the signature of a person who should be dead.》

Mio's hand stopped.

At the end of the recording, her father announced this.

"Do not blame the professor. He was hesitant until the very end."

The tape cut off there.

Silence fell over the room.

Mio could not say anything.

Is her father alive?

Is he dead?

She still did not know.

But she understood one thing.

The incident was not about the theft of cultural assets.

It was an incident of erasing people's names and rewriting the past.