The notification arrived just as dawn painted the sky above Moo66 in soft shades of gold.

It was not from the local town.

It came from another region.

From the Asia Server.

Leemai, the elegant manager of LEEMAI Guest House, had sent an urgent message.

She rarely interrupted anyone’s daily routine.

If she did…

It meant something important was about to begin.

Leemai’s voice sounded calm, although slightly weaker than usual.

She paused for a moment before continuing.

Usinomics blinked.

Leemai nodded.

She smiled gently.

Usinomics checked his travel bag one more time.

Leemai laughed quietly.

Usinomics smiled.

Leemai waved softly.

The communication ended.

Usinomics looked toward the horizon.

Before the event officially began, life continued as usual.

Fishing.

Collecting resources.

Greeting visitors.

The peaceful rhythm of Moo66 never truly stopped.

Later that afternoon, Usinomics boarded Fishing Boat No.1, where a seasonal fishing event was already underway.

Several residents quietly joined him.

One young fisherman barely spoke.

Instead, he spent most of his time sitting comfortably on the deck, occasionally lifting his binoculars to scan the distant horizon.

No unnecessary conversation.

No dramatic introductions.

Just quiet understanding.

Usinomics eventually sent him a friend request.

Accepted.

From that point onward…

An unspoken fishing competition began.

No rules.

No prizes.

No words.

Only patience.

Only skill.

Only the gentle sound of waves beneath the wooden boat.

Fish after fish filled their baskets until the event quietly came to an end.

Then…

The world trembled.

A deep vibration echoed beneath the sea.

The dock shook violently.

Buildings rattled.

The ground groaned.

An earthquake.

Immediately, another notification appeared.

All available investigators were requested to report to the town restaurant.

Usinomics hurried over.

To his surprise, today’s gathering wasn’t a formal emergency meeting.

Instead…

Everyone was eating.

The local administrators had decided to continue dinner while discussing the situation.

Usinomics quickly prepared several simple homemade dishes.

Nothing extravagant.

Fresh salads.

Warm pasta.

Comfort food.

Exactly what exhausted workers needed.

While everyone ate together, officials explained the situation.

The underwater region had become unstable.

Several marine zones required immediate investigation.

Before Usinomics could quietly slip away…

His name appeared on the assignment list.

Marine Investigation Team.

He sighed.

After helping clean the restaurant, Usinomics returned home.

Preparation became his next mission.

He opened the storage cabinet.

Forty freshly prepared salads.

Two containers of pasta.

Vacuum-packed for long expeditions.

Extra clothing.

Medical supplies.

Everything carefully packed into his travel bag.

Standing in front of the mirror, he looked at his usual outfit.

Heavy clothes would absorb water.

Swimming would become exhausting.

He changed into lighter clothing designed for movement.

Not diving gear.

Just practical travel clothes.

He looked ready.

At least…

Ready enough.

The ocean greeted him with complete silence.

Unlike ordinary seas…

This underwater world contained breathable air.

Walking beneath the surface felt strangely natural.

Yet every action drained physical strength far faster than life on land.

Colorful coral forests stretched across the seafloor.

Schools of tiny fish drifted between ancient rock formations.

White domed buildings rested peacefully beneath the waves, making the underwater city resemble a forgotten civilization.

Occasionally, shimmering bubbles floated upward like tiny stars.

Everything felt beautiful.

Everything also felt dangerous.

As Leemai had warned…

Dark patches of contaminated seawater spread throughout the area.

Whenever Usinomics approached clean coral, he felt an immediate sense of relief.

Almost as if invisible impurities had been washed away.

He quietly smiled.

Still…

He refused to stay longer than necessary.

He returned home once to bathe, completely removing any remaining contamination before continuing the expedition.

Safety came before pride.

Always.

The second investigation carried him deeper into the ocean.

The cliffs grew taller.

The light grew dimmer.

Ancient stone formations surrounded him like underwater mountains.

Then…

A massive shadow appeared.

Slowly.

Gracefully.

A giant ocean sunfish drifted through the blue silence.

It wasn’t aggressive.

It simply floated through the current as though it had ruled these waters for centuries.

Usinomics stopped moving.

He watched without speaking.

The enormous creature disappeared into the endless blue.

For several quiet moments…

There was nothing except the soundless movement of the sea.

Usinomics smiled beneath the shimmering water.

The investigation had only just begun.

Far beyond the coral forests…

The ocean still held countless mysteries waiting beneath its endless blue horizon.

The preparations were finally complete.

Well…

Almost.

Before leaving, Usinomics noticed something rather unusual.

Shamnomics had apparently mastered another very important life skill.

The elegant Siamese cat had lifted one hind leg and was enthusiastically scratching behind one ear.

The expression on his face gradually became more ridiculous.

His eyes rolled halfway upward.

His mouth slowly fell open.

His entire body relaxed as though he had discovered the greatest luxury in the universe.

Usinomics folded his arms.

He watched silently.

Shamnomics continued scratching without acknowledging him.

For a brief moment…

Nothing in Moo66 seemed more important than a satisfied cat.

Usinomics couldn’t help smiling.

Sometimes…

Heroes simply had to wait until the cat finished.

With everything finally packed, Usinomics climbed into his vehicle and drove toward the coast.

The road stretched peacefully beneath a brilliant summer sky.

Soon, the massive Marine Investigation Gate appeared before him.

It shimmered with an emerald-blue light.

Beyond it…

Another world waited.

As soon as he crossed the gateway, the scenery transformed.

An endless underwater kingdom unfolded before his eyes.

Schools of tiny silver fish drifted gracefully through the current.

Crystal-clear blue-green water reflected the sunlight above, illuminating the ocean like the ceiling of a magnificent cathedral.

The sea didn’t feel heavy.

It didn’t even taste salty.

Instead, it felt surprisingly comfortable.

Fields of sea grass and towering kelp gently released streams of oxygen into the surrounding water.

Rock formations stood perfectly clean.

No algae.

No slime.

No decay.

Everything appeared untouched.

Peaceful.

Beautiful.

Almost too beautiful.

Every resident had gathered for the investigation.

Nobody had been forced to participate.

Yet almost everyone had shown up anyway.

The event felt less like emergency work…

…and more like an underwater community adventure.

Usinomics slowly descended toward the seafloor.

His movements became smoother with every stroke.

Then…

He found it.

A gigantic coral formation.

Bright streams of oxygen poured continuously into the surrounding water.

The moment he approached…

The contamination warning disappeared.

He blinked.

Leemai had been right.

Again.

The deeper he traveled…

The quieter the ocean became.

Eventually, he discovered something enormous resting across the seabed.

At first…

It looked like ancient ruins.

Then he realized what it truly was.

The massive skeleton of a whale.

Its ancient bones stretched across the ocean floor like the remains of a forgotten civilization.

Time itself seemed to have fallen asleep there.

Usinomics stood silently before the silent giant.

His voice disappeared into the endless blue.

Around him…

Thousands of tiny fish moved together as one living current.

Corals swayed gently.

Seaweed danced peacefully with the tide.

Every plant quietly continued producing oxygen.

Life supported life.

Without asking for recognition.

Without expecting applause.

Then…

The beauty suddenly changed.

Dark clouds drifted through the water.

Small at first.

Then larger.

Black spheres of contamination floated between the coral forests.

Everything they touched slowly lost its natural color.

Healthy marine life faded into dull gray.

The ocean itself appeared to be growing sick.

Usinomics narrowed his eyes.

After documenting the contaminated zones, he submitted his investigation report.

A notification immediately appeared.

LEVEL UP

Advanced Investigator Rank Achieved

A second notification followed.

New Equipment Unlocked

A waterproof purification device materialized inside his equipment case.

Its compact metallic design was surprisingly lightweight.

Yet it contained enough purification energy to remove contamination directly from the surrounding environment.

Usinomics turned it over in his hands.

He returned safely to Moo66 before sunset.

The investigation map spread across the dining table.

Four separate marine sectors.

Each one farther away than the last.

Some required traveling through winding underwater caves.

Others lay beyond enormous coral valleys.

Every route demanded careful planning.

There would be no room for mistakes.

Food consumption alone would become a serious issue.

Usinomics quietly studied every route.

Again.

And again.

He memorized the safest paths.

Nearest purification coral.

Emergency exits.

Return gates.

Current directions.

Everything.

If contamination reached dangerous levels…

Retreat immediately.

If retreat became impossible…

Reach the purification coral.

Never lose sight of the nearest gate.

Never lose track of the compass.

Getting lost beneath the ocean wasn’t simply inconvenient.

It could become permanent.

Usinomics stared at the map for several seconds before quietly speaking to himself.

Silence answered him.

Then Shamnomics walked past.

The Siamese cat glanced at the map…

Looked at the purification device…

Looked at the backpack filled with forty salads…

Then casually curled up beside it and fell asleep.

Usinomics laughed.

He carefully closed the backpack.

Inside rested everything he would need.

The waterproof purification device.

Fresh clothing.

Emergency supplies.

Forty homemade salads.

Two containers of pasta.

Tomorrow…

The real underwater expedition would finally begin.

The afternoon sun shimmered across the shoreline as Usinomics returned to the beach.

Today was different.

This was no sightseeing trip.

This was another deep-sea investigation.

He checked his equipment one last time.

A waterproof explorer’s outfit.

A contamination removal device.

Emergency food supplies carefully packed inside his bag.

Everything was ready.

Without hesitation, he stepped through the Deep Sea Gate.

The world dissolved into blue.

An instant later, gravity disappeared.

The ocean embraced him.

Tiny bubbles floated toward the shimmering surface while schools of fish glided peacefully overhead.

Usinomics raised the purification device in one hand and slowly descended into the depths.

The deeper he swam, the quieter everything became.

Ancient coral forests stretched endlessly before him.

Seaweed drifted gently with the current.

Yet something was terribly wrong.

Large sections of coral had lost their brilliant colors.

Dark floating spheres clung to rocks, sea plants, and the ocean floor like a spreading disease.

Usinomics activated the purifier.

One by one…

The black contamination dissolved.

Cloudy water cleared.

Faded coral slowly regained its vibrant colors.

Sea plants straightened as if breathing again.

The ocean itself seemed to sigh with relief.

Usinomics smiled.

He looked across the endless seafloor.

No one answered.

Only the currents whispered.

He continued deeper.

Ancient ruins rested silently beneath the sea.

Coral-covered caves twisted through enormous rock formations.

Even these forgotten places had been touched by the mysterious pollution.

Wherever he cleaned, beauty returned.

Bright corals glowed again.

Colorful sea fans unfolded.

Tiny fish cautiously returned to their homes.

It almost felt as though the ocean had simply been waiting for someone to help.

Nearby, graceful fish swam carefully around the remaining contaminated areas, instinctively avoiding danger.

As if they had already learned to survive.

Further ahead, Usinomics discovered a collapsed rock formation.

Hidden inside…

A beautiful glowing shell.

It was trapped beneath the rubble.

He examined it carefully.

He nodded.

Some treasures simply required patience.

The cave became darker.

Jellyfish floated silently through the water like glowing lanterns.

Inside the cavern, contamination covered nearly every coral colony.

Even worse…

Black particles drifted freely through the current.

Suddenly—

The contamination struck.

Dark spheres clung to Usinomics’s suit.

Warning indicators flashed.

His breathing grew heavier.

His vision blurred.

He looked around.

No emergency healing coral.

He had ventured far too deep.

Then…

Someone appeared.

Another diver.

Another explorer.

Without wasting a second, Usinomics waved both hands and immediately sent a friend request.

Accepted.

The diver responded with a cheerful sticker.

Relieved, Usinomics offered the only thing he happened to have with him.

A plate of pasta.

She accepted it happily.

Then Usinomics smiled.

She laughed.

“Hi!”

Without saying another word, she activated her own purification device.

The contamination surrounding Usinomics vanished almost instantly.

He was safe.

Pure water surrounded him once again.

Unable to contain his excitement, Usinomics spun through the water like a joyful dolphin.

His rescuer laughed…

…and spun right beside him.

Then, to his surprise, she handed him an even more luxurious meal than the one he had offered.

His stomach had been growling for quite some time.

He accepted it with a grateful smile.

If you ever read this story…

There is something I want to tell you.

Thank you for saving me.

From the bottom of my heart.

With sincere gratitude.

Feeling slightly embarrassed by the unexpected kindness, Usinomics gave one final wave before quietly swimming toward another section of the reef.

Hours passed.

The final traces of contamination disappeared.

Crystal-clear water returned.

Sunlight reached the ocean floor once again.

Fish swam freely through glowing coral forests.

The underwater world had come back to life.

Then…

Something caught his eye.

A massive vehicle rested silently nearby.

Its searchlight still illuminated the darkness.

No one was inside.

The hatch remained sealed.

Whatever story it held…

Would have to wait for another day.

On the journey back, Usinomics gathered seaweed for tomorrow’s supplies.

Along the way, another explorer appeared.

A new friend.

Instead of words…

They communicated through cheerful emotes and underwater dances.

Laughter required no translation.

Finally, Usinomics smiled.

His new friend smiled back.

“Thank you.”

That simple exchange somehow said everything.

Feeling just a little shy again, Usinomics waved goodbye and headed toward the Deep Sea Gate.

The familiar shoreline welcomed him home.

Warm sea breeze replaced the cool ocean currents.

Without hesitation, he climbed into his little car and drove straight back to Moo66.

The first stop…

The bath.

Steam filled the room as he sank into the warm water.

The exhaustion slowly melted away.

Tomorrow’s equipment.

Tomorrow’s clothes.

Tomorrow’s food supplies.

He planned everything while relaxing in the tub.

Eventually…

He walked into the staff room, intending to take only a short nap.

Five minutes.

That was the plan.

Instead…

Usinomics fell into a deep, peaceful sleep.

Outside, Moo66 quietly prepared for another adventure.

And somewhere beneath the waves…

The ocean waited.

Not as an enemy…

But as a friend with many more secrets still left to discover.

End of Chapter 42