The Kamogawa Delta Cipher | Chapter 5: The Stepping Stones at Night

On Thursday night, there was no one at the Kamogawa Delta.

It was as if the daytime bustle had been a lie.

Rain is coming.

The sky is low, and the light from the streetlamps is blurred in the damp air.

Only the sound of the river was louder than usual.

Mio looked down at the stepping stones from the bridge.

The email that arrived yesterday was displayed on her smartphone screen.

《Thursday, the stepping stones will sink》

Yuma looked at his wristwatch beside her.

11:42 PM.

What's the water level?

It's rising little by little. It might have rained upstream.

Yuma was checking the water level information on his smartphone.

He had the touch of an engineering student.

He looks at the numbers before his emotions.

Mio trusts that part of him a little.

What about Rui?

He said he isn't coming. Apparently, he was called by a professor.

By a professor?

Yeah. Suddenly.

Mio did not reply.

It was too well-timed to be a coincidence.

As they descended to the riverbank, the grass was damp.

A small sound came from underfoot.

Crunch.

It was a sound that would be nothing during the day.

But by the river at night, it sounded strangely loud.

"Are you really going?"

Yuma asked.

"Are you scared?"

"Of course I'm scared. It's a river at night, after all."

"Honesty is a virtue."

"You..."

Mio smiled slightly.

The more nervous Yuma was, the more he talked.

He seemed scared, yet he wouldn't run away.

Mio believed that was a form of kindness.

Though he probably didn't realize it himself.

I place my foot on the first stepping stone.

It is cold.

Dampness seeps through the soles of my shoes.

The river surface is black, stretching the streetlights into thin lines.

Places that look like playgrounds during the day are different at night.

The water does not invite anyone in.

It simply exists there in silence.

Mio moved to the second stone.

The white line that was visible yesterday is almost completely submerged.

It swayed vaguely beneath the surface of the water.

"The reflection will appear in just a little while."

Yuma said.

"When the angle of the streetlights and the water level align, the symbol will be complete."

"You remembered that well."

"That's because someone's explanation was so long."

Mio crouched down.

The white line distorted in the water.

A semicircle.

A diagonal line.

A triangle.

They connect and separate in time with the waves.

The cipher is not drawn on the stones.

It appears between the stones, the water, and the light.

That is why you cannot understand it from photographs alone.

You cannot read it unless you come to the site.

"The person who made this really knows how to read the water levels."

Yuma said.

"It's not just ordinary graffiti."

"Yeah."

"They have knowledge of civil engineering or water management."

Mio nodded.

And then, she held her breath.

On the opposite bank.

A figure moved.

A black hat.

A low posture.

Someone was coming down to the stepping stones from the shadow of the bridge.

Yuma noticed it too.

The two of them did not make a sound.

The figure was holding something in their hand.

A small can.

White paint.

The figure approached the stone with movements devoid of hesitation.

Then, they crouched down at the water's edge.

Mio started the recording on her smartphone.

Yuma whispered.

"Should we call the police?"

"Not yet."

"What do you mean, not yet?"

"I want to see what they're drawing."

Yuma looked exasperated, but he stayed silent.

The figure took out something like a brush.

It was their left hand.

Without hesitation, they drew a line on the edge of the stone.

A thin straight line.

Next, a small dot.

Then, a semicircle.

Mio did not miss it.

The position they were drawing in was now right at the water's surface.

It will sink in another ten minutes.

In other words, this symbol also assumes that it will become invisible.

"Left-handed"

Yuma muttered.

"The foreshadowing from Chapter 5 is being resolved, isn't it?"

"What are you talking about?"

Mio smiled slightly.

But the next moment, the stone under her feet became slippery.

Her body swayed.

Yuma grabbed her arm.

"Watch out."

"Thanks."

The distance between them was close.

In the cold air of the night river, only Yuma's hand was warm.

Mio pulled her arm away immediately.

"I'm fine."

"Are you really?"

"Yeah."

Yuma looked like he wanted to say something.

But he didn't.

There are things that break when you put them into words.

Mio knows this.

At that moment, the figure over there looked up.

They noticed us.

Let's go!

Yuma started running.

Wait!

Mio followed.

They crossed the stepping stones.

The night water surface splashed at their feet.

The figure climbed up to the riverbank and headed north.

They are fast.

But they are not used to running.

Their shoulders are swaying.

Yuma closed the distance.

Stop!

The voice echoed through the night.

The figure did not look back.

Instead, they threw something.

A small metallic sound.

Yuma stops in his tracks.

"Whoa."

A can rolled at his feet.

A white liquid spilled out.

It was paint.

In that instant, the figure vanished beneath the bridge.

Mio and Yuma gave chase.

The shadow of a bridge pier.

Damp concrete.

The scent of water.

But there was no one there.

"They disappeared?"

Yuma is out of breath.

Mio looked around.

Not toward the river.

No signs of them climbing up, either.

Then.

"Below."

"Below?"

Mio shone her light beside the bridge pier.

There was a dark gap in a section of the old stone masonry.

It was wide enough for one person to pass through.

Normally, it would be hidden by weeds and shadows.

But now, there were footprints left in the mud near the entrance.

Wet footprints.

They looked similar to the ones I saw in the archives.

"An underground passage..."

Yuma's voice dropped low.

Mio knelt down and checked the prints.

The pattern of the soles.

The outer edges were worn down.

It's the same person.

"Are we going in?"

"No."

Mio said.

"It's too dangerous right now."

"It's actually scarier when you're the one saying that."

"It's just a normal judgment call."

"Your 'normal' isn't normal, though."

Mio took a photo of the entrance with her smartphone.

At that moment, something appeared on the screen.

Inside the entrance.

On the wall surface.

A white symbol.

A single line in the center of a triangle.

The mark of a closed waterway.

But there was another one next to it.

A small character, looking like a kanji.

Mio zoomed in.

“Water...?”

No, that's not it.

It's an old script.

“Eternity.”

Yuma peered over.

“Eternity?”

“It can also mean that water flows for a long time.”

“That sounds like Kyoto.”

“But I don't understand why it would be written here.”

Mio looked at the screen even more closely.

Next to the characters, there are faint numbers.

31.

No.

If you turn it upside down, it's 13.

"Thirteen...?"

Yuma said.

"What kind of number is that?"

Mio couldn't answer.

But her heart began to beat a little faster.

She felt like there were similar numbers in her father's notebook, too.

The two of them returned to the riverbank.

They picked up the discarded paint can.

The label had been peeled off.

They couldn't expect to find any fingerprints either.

But on the bottom of the can, a small sticker remained.

"This is an inventory sticker from an art supply store."

Yuma said.

"What's the store name?"

"I can read it. It looks like a shop in Teramachi."

Mio memorized it.

Teramachi.

A street lined with old bookstores and art supply shops.

In Kyoto, old paper and new paints are sold on the same street.

A town where the past and the present sit side by side as if it were the most natural thing in the world.

By the time it was past midnight, the stepping stones had almost submerged.

The new symbols drawn by the shadows of people were also hidden by the water.

But, the moment the reflection of a streetlamp raced across the water's surface.

The cipher was complete.

Mio gasped.

White lines overlapped within the water's mirror.

What appeared there was neither a direction nor a number.

A single arrow.

Not south.

Southeast.

"Southeast...?"

Yuma opened the map on his smartphone.

Southeast from the Kamogawa Delta.

What lies on that extension.

The university.

And, further ahead.

"It's in the direction of Nanzen-ji Temple."

Mio stared at the screen.

Nanzen-ji Temple.

The Suirokaku Aqueduct.

The Lake Biwa Canal.

The path of water her father had been chasing.

Everything was becoming a single line.

That night, Mio couldn't sleep even after returning home.

On her desk lay her father's notebook.

Photos taken at the Kamogawa River.

Paint cans.

Screenshots of the video.

The evidence had increased.

But the mystery was deepening.

Who is drawing the symbols?

Why did they spread them on social media?

Why is the same mark in her father's notebook?

And then.

Is the person in the hat really an enemy?

Mio played the recording.

The scene where the person draws a line on the stone.

The left hand.

Wet shoes.

A small build.

The way they run.

At that point, Mio paused the video.

Something is visible on their wrist.

A thin red string.

Like the kind of amulet string sold at temples and shrines in Kyoto.

But the knot is different.

A Chinese knot.

“...Derived from Chinese.”

The words that were supposed to lead to Chapter 6 quietly took shape within Mio.

Her smartphone vibrated.

An email from an unknown address.

The body of the message was one line.

“Next, look at the paper, not the stone.”

There are no attachments.

Mio opened her father's notebook.

Tucked into the edge of the page was a small scrap of paper she had overlooked many times.

Old Japanese paper.

On it, only a single character was written.

—Storehouse.