1:58 a.m.

The wind was light.

The lights outside Taka Square,
one after another,
were still on.

Not the bright kind of liveliness.

It was the kind of brightness that remained after a mall had closed,
yet still refused to fully fall asleep.

A little cold.
A little empty.

Almost like—
a city taking one last look at itself
before closing its eyes.

Su Mei Mei,
twenty-two years old,
a Computer Science student from Central City University.

She was sitting by the stairway.

Leaning against a pillar.

Her head tilted slightly to one side.

Her hands hanging naturally.

As if she were waiting for someone.
As if she were daydreaming.
As if she had simply been too tired,
sat down for a while,
and fallen asleep.

But she was not asleep.

She had been motionless for quite some time.

The first person to spot her
was the night-shift security guard.

He was patrolling the perimeter,
his flashlight sweeping slowly across the ground.

The stairs.
The handrail.
The edge of the planter.
The reflection in the glass doors.

Everything looked normal.

Until the beam of light
fell on that seated figure.

He stopped.

Frowned.

At that hour,
no one should still have been sitting there.

He stood where he was for two seconds.

Did not move.

The girl did not move either.

He called out.

“Miss?”

No response.

He walked closer.

His leather shoes tapped against the stone tiles,
crisp and monotonous.

One step.
Another.
Then another.

The night was too quiet.

The sound of it,
for some reason,
made the emptiness inside him grow.

He called again.

“Miss, are you alright?”

Still no response.

He was now only two steps away from her.

This time,
he saw clearly.

The girl’s eyes were open.

Not wide.

But empty.

Empty,
as if no one was inside.

The guard felt his heart sink.

Sweat

immediately crept down the back of his neck.

Instinctively,
he took a breath.

And then—

he smelled it.

A scent.

Very faint.

Very light.

Not the cloying sweetness of cheap perfume.

This was more refined.
More delicate.
More quiet.

Like dry fig leaves
softly rustling in the morning light.

Like a luminous trace of orange blossom
gliding through the air.

Behind it lingered a herbaceous woodiness,
clean,
restrained,
as if someone had ground an entire forest into the finest powder
and brushed it against the nerves.

But hidden within it
was something else.

White.
Soft.
Barely sweet.

Like the last shadow
left behind by white oleander in the night.

He inhaled again.

His head
suddenly swam.

Not heavily.

But unmistakably.

As if someone had taken a needle
and lightly touched the back of his temple.

He instinctively held his breath.

His heartbeat quickened.

He lifted a hand
and cautiously touched Su Mei Mei on the shoulder.

“Miss—”

The moment he touched her,

her whole body
slumped sideways at once.

No struggle.
No reaction.

It was like something that had already lost all support,
simply sliding down.

The guard’s face turned pale instantly.

“Hey! Hey!”

He stumbled back two steps,
almost tripping over the stairs.

He grabbed his radio at once.

“Guard house, guard house, respond! Stairway east side! One female down! No response! Call police! Call ambulance now!”

His voice was shaking.

So fast it almost broke.

With his other hand,
he had already pulled out his phone
and dialed 999 directly.

The night was still there.

But the air
had changed.

Eight minutes later.

Two police cars
cut into the outer edge of the square,
one after the other.

Doors opened.

Four police officers stepped out.

They moved quickly.

Calmly.
Professionally.

One officer went to the security guard first.

“Calm down and tell me exactly what happened.”

Another crouched down,
put on gloves,
and made an initial check on Su Mei Mei.

The other two pulled up police tape
and began sealing off the scene.

The stairway.
The outer walkway.
The pillar side.
The planters.

Every point where someone could have approached,
paused,
deployed something,
or observed the area,
was immediately marked off.

When I later reviewed the scene records,
I could tell at once
that the first four officers on site
had made no mistakes.

They did not touch too many things.

They did not rush to conclusions.

They did not allow the scene to fall apart.

That was a good thing.

Because from the very beginning,
this case
was abnormal.

During the first police assessment,
there were no obvious external injuries.

No signs of struggle.

No signs of robbery.

Her belongings were still there.

Her bag was still there.

Her phone was still there.

Her shoes were in place.

Her hair was undisturbed.

She had simply—
been sitting there.

As if something
had quietly switched her off
from inside her own body.

A few minutes later,

the Forensic Science Division arrived.

The first team on scene
was the Scene of Crime & Quality Management Section.

Leading them
was Dr. Cheng Kok Ming.

As he stepped out of the vehicle,
he was already putting on gloves
while lifting his eyes to study the stairs, the wind direction, and the surrounding light sources.

He was not a man of many words.

But his eyes were fast.

Most people looked at a scene.

He read it.

The three team members who came with him
split up immediately.

One photographed the overall environment.

One measured positions,
marked objects,
and established scene reference points.

The third checked for possible contact surfaces and trace evidence.

Almost at the same moment,
another vehicle pulled in.

The Chemical Sciences Section had arrived.

Leading them
was Sum Kwok Tong.

Of his four team members,
two carried air-sampling devices,
one prepared to collect surface residue,
and one set up a portable detection instrument.

Their movements were even lighter.

Because they knew
there might be something invisible at this scene.

Dr. Cheng Kok Ming crouched before Su Mei Mei.

He did not speak immediately.

He first examined her complexion.

Her pupils.

The edge of her lips.

Her fingertips.

Then he looked up at the security guard and asked,

“When you first approached her, did you smell anything?”

The guard froze for a moment.

“Yes… yes, a scent.”

“What kind of scent?”

“Like… like a very expensive perfume, but I can’t describe it. If you breathe it in too much, you feel dizzy.”

A shadow passed through Dr. Cheng’s eyes.

He did not turn around.

He only said one sentence.

“Sum Kwok Tong. Air sample first.”

Sum Kwok Tong was already doing it.

He stepped to the middle section of the stairs,
stopped,
and raised a hand to signal his team not to take deep breaths.

Then he slowly inhaled once himself.

Only once.

His brow immediately tightened as well.

“It’s here,” he said.

“Very faint. But it’s here.”

The next second,
he turned to his team.

“Upgrade all masks. Divide the sampling into three zones. The stairs, the pillar surface, and everything within one meter of the victim. Do them all.”

The air at the scene
suddenly felt even quieter.

Because everyone understood—

what they were smelling
was not a coincidence.

It was evidence.

Two minutes later.

Paradise Island’s upper leadership received the full report.

The fourth case.

The same seated posture.
The same structural type of location.

No obvious external injuries.
The same abnormal scent.

This time,
no one called it coincidence.

Paradise Island—

the meeting point of wealth, power, and illusion.

An island too prosperous,
and too sensitive.

Here,
if a case was merely a case,
the handling would be simple.

But once a case began to repeat itself,
began to form a pattern,
began to suggest
some kind of invisible assault,

it stopped being merely a policing matter.

When the fourth scent murder case appeared:

Prime Minister: Huo Feng.

Ministry of Justice: Liu Xin Min.

Commissioner of Police: Lin Zhong Mou.

Only one order remained:

The case must be solved.

And it must be solved quickly.

Thus—

SID, the Special Investigation Division, was formed.

And I,
Yong Tin Kei,
was pushed into
a position where failure was not allowed.

2:27 a.m.

We arrived.

Two black operations vehicles
glided silently to a stop outside the cordoned area.

I got out first.

The wind came lightly from the stairway.

But the moment I stepped out,
I smelled it.

That scent,
extremely faint.

Not violent.
Not sharp.
Not overtly aggressive.

And that was exactly what made it dangerous.

The things that truly kill,
most of the time,
do not like to announce themselves first.

I took one look at the scene.

Then I spoke.

“Hsin-Yan, read the victim.”

“Wai Hing, read the objects.”

“Yim Bing, read the lines.”

“Chih Lin, pull every electronic trace.”

“Min Jung, get me surrounding surveillance, heat sources, wireless signals, and airflow data.”

The five of them
moved without a word.

Each went to work.

Chang Hsin-Yan approached Su Mei Mei first.

She did not touch the body.

She simply stood half a step away
and looked.

At the face.
At the posture.
At the clothing.
At the natural bend of the fingers.
At the direction of the shoe tips.
At the looseness of the shoulders.

What she was best at
was never finding what was visible.

It was finding
what did not fit human nature.

Lee Wai Hing moved slowly around the scene.

The handrail.
The edge of the pillar.
The gaps between floor tiles.
The soil surface in the planter.
The opening of the trash bin.
The drainage seams.

Every position where something could have been hidden,
left behind,
deployed,
removed,
or observed from—
he would miss none of them.

Yim Bing stood farther away.

She did not hurry into the center.

She first studied the outer sightlines.

Sniper instincts
always made her ask first:
where would someone stand to watch you?

High points.
Blind spots.
Escape routes.
Intersecting lines.
Suppression points.

What she was reading
was not the crime scene.

She was reading
how an enemy would use the scene.

Tan Chih Lin was already online.

His tablet linked to the mobile command system
and began pulling feeds from around Taka Square:
public surveillance,
private camera angles,
parking records,
short-duration wireless device activations,
temporary Bluetooth signals,
abnormal network hop points.

What he investigated
was not people.

But the shadow
that traces left behind in data.

Kim Min Jung was even more direct.

She placed a portable environmental sensor at the wind point,
while simultaneously pulling nearby mall ventilation records,
crowd heat maps,
and the turning dead angles of the outer wall surveillance cameras.

When she stared at a screen,
she was like a silent hawk.

No emotion.

Only lock-on.

I walked over to Dr. Cheng Kok Ming.

“Status?”

He stood up,
removed one glove,
and looked graver than usual.

“Initial observation: no external injuries. No clear signs of struggle. Before respiratory arrest, she likely made no large-scale defensive movements.”

“Poisoning?”

“Not concluding that yet. But the same scent is present.”

“The same as the previous three cases?”

He looked at me.

“Very close. Possibly the exact same one.”

I did not speak immediately.

I just looked up at the stairway.

Stone steps leading upward.

Light coming down from above.

The victim’s position
sat precisely between light and shadow.

Suddenly,
I felt that the enemy was not killing people.

It was as if he were arranging exhibits.

Calm.
Orderly.
Repetitive.
And—
deliberate.

“What about Sum Kwok Tong’s side?”

Dr. Cheng glanced over.

“They’re sampling now. Air, clothing, pillar surface, stair surface. Initial reaction suggests a volatile composite substance, but it’s too fine. We’ll need the lab.”

“Enough to make a person dizzy?”

“In theory, yes. Possibly more than dizzy.”

I looked at Su Mei Mei.

She was very young.

Young enough
that life had not yet truly worn down the lines of her face.

But she was already dead.

Dead beside a shopping plaza stairway.

Dead so quietly.

As if no one had ever touched her.

Cases like this
were the easiest to misjudge.

Because they did not shout.

The dangers that do not shout
are often the deepest.

I crouched down
and looked at her once.

Then I stood up.

“Merge all three previous cases into SID. Victim backgrounds, social circles, course lists, online activity, spending records, movement history. I want all of it. Miss nothing.”

Tan Chih Lin answered from behind me.

“Understood.”

“Min Jung.”

“Yes.”

“Overlay the airflow, surveillance blind spots, and suspicious stop points from all four scenes. I want to know whether this looks like the work of the same setup mind.”

“Understood.”

“Hsin-Yan.”

“Yes.”

“Start with the victims’ common traits. Not surface-level. I want the deepest connection between them.”

Chang Hsin-Yan nodded.

“I’m already thinking about it.”

“Yim Bing.”

“Yes.”

“Assume this is not a lone killer, but a small deployment team. Give me three most likely scene deployment models.”

She looked at the stairway
and said only one word.

“Alright.”

Finally, I looked at Lee Wai Hing.

“Lee.”

He did not turn around.

He was still examining the base of the pillar.

“Mm.”

“I don’t believe the other side left nothing behind. Turn this place inside out for me.”

Lee Wai Hing replied calmly with one sentence.

“So do I.”

By the time the sky was about to break,
the scene work was finally winding down.

The body was transported.

The samples were sealed.

The first layer of reports
was transmitted directly to the SID operations room.

4:12 a.m.

SID Operations Room.

All lights on.

All screens active.

For the first time,
the files of all four cases
appeared side by side on the main screen.

Lin Bing.
Hong Yu.
Tan Xin Yi.
Su Mei Mei.

Four young faces.

Four death postures so similar
they seemed almost intentional.

Four locations.

Two universities.
Three urban points.
The same scent.

I stood before the screen,
silent.

Dr. Cheng Kok Ming stood at my right,
placing his initial record board on the table.

“One thing can now be confirmed.”

I turned to look at him.

“Say it.”

“These four cases are absolutely not independent incidents.”

No one in the operations room spoke.

Because in truth,
everyone already knew it.

Only now,
it had finally been said aloud.

“What else?” I asked.

Dr. Cheng paused for a second.

“If our judgment is correct—”

“then what the killer used
was not only a toxin.”

“It was a deliberately designed scent carrier.”

The air in the room
seemed to fall silent all over again.

Chang Hsin-Yan looked up.

Tan Chih Lin stopped typing.

Kim Min Jung’s eyes narrowed slightly.

I looked at Dr. Cheng Kok Ming.

“You mean someone hid the killing mechanism inside a scent?”

“Yes,” he said.

“And the method is highly sophisticated.”

Slowly,
I turned my gaze back to the screen.

The four victims
seemed to be looking at us in silence.

The lights were white.

The operations room was cold.

And then I understood—

what we were hunting
was not an ordinary killer.

What we were hunting
was something invisible,
something you could smell,
but not defend against in time.

And this city,

might only just have begun
to smell it.