Chemistry

Chapter 85

Research Building No. 1, Integrated Air Purification System Test Lab.

A 1m² model house, replicating a whole floor of the building, sat on the table.

Jeong-woo turned his head towards the filter team, who were preparing for the test on one side. He met eyes with Kim Tae-san, who smiled and raised his thumb at Jeong-woo.

It would take a few days to revise the comments on the semi-permeable filter handed to Ha Won-il, but the 5-stage filter was ready to go.

Jeong-woo was also eager to see the results.

There was still some problems so he had spent the afternoon with the filter team and hadn’t had a chance to talk to Mei.

‘What could be the reason?’

While pondering, the measurement by the equipment team began.

They visually inspected the model house and continued with leakage tests of the mini-frame and air flow distribution tests.

『We will begin the wind speed test.』

The roof of the model house was covered with a round dome-shaped glass.

A 3D model appeared on the monitor, allowing them to see inside the model house. The wind information quantified as it followed the fan’s movement.

Mei watched closely and pointed to one part.

『The last room doesn’t have enough wind speed.』

『It’s because it’s the farthest place structurally, and there’s no way to increase the wind speed more than this without adding another line…』

『In a building that can only use the existing ventilation line, it’s an impractical method.』

The equipment team’s expert couldn’t respond immediately, then spoke as if he felt unfair.

『This is impossible for any company due to the structure.』

『Impossible? Does that mean we have to tell the people in the last room to breathe bad air due to the structure? It sounds like you’re telling me to give up on next week’s bidding.』

During their conversation, Jeong-woo shifted his gaze to the model house rather than the monitor. The ventilation fan on the exterior wall was constantly running, but it seemed like it couldn’t quickly remove all the air inside.

Mei turned to the filter team and said.

『Please add a bypass filter for internal circulation in the area with insufficient wind speed.』

Kim Tae-san immediately objected.

『Why are you burdening the filter team with a structural problem from the equipment team?』

『Aren’t we the ones making a system like this?』

『You seem to be misunderstanding something. We want clean air, not a clean room. Even if the wind speed is insufficient, we can cover it with our 10-stage filter.』

『It seems there’s a significant gap in opinions about breathable air between Mr Kim and me. I’m sorry.』

“I regret meeting this woman. Regret.”

Kim Tae-san muttered.

Just like the morning meeting, the atmosphere grew tense, Jeong-woo had no choice but to look around. The equipment team remained silent on their own, and the sensor and filter teams stared sharply at each other.

‘I wonder if I’ll ever make a good impression on the team leader like this.’

Jeong-woo, who was anxiously looking at those teams, noticed Ha Won-il.

“Assistant Manager Ha.”

Ha Won-il answered in a small voice, “Yes?”

“The bypass filter. Shall we make it ourselves?”

“Now?”

“It’s a small one, so we can do it quickly.”

Ha Won-il hesitated and pointed to the room across from them.

“All our clean filter tools are in the second lab.”

Jeong-woo and Ha Won-il, who had briefly stepped out of the integrated inspection room, immediately entered Experiment Room No. 2.

Jeong-woo donned his gloves and turned his attention to the KG Electronics air purifier filter sample neatly arranged on the table.

The filter looked like layers of stacked paper. It was cut to the size that would fit into the model house’s ventilation line.

“Is this size sufficient?”

“It’s more than enough. I’ll take care of making the bypass connection.”

Ha Won-il also began assisting Jeong-woo with his work.

‘Let’s stay calm.’

The performance of the nanoscale filter and absorption membrane, confirmed through a molecular perspective, was optimized for the molecular structure that allowed water to flow as desired. KG Electronics’ technology, which transformed it into a form usable for air, was excellent. However, achieving optimal efficiency in the battle against ultrafine particles was challenging.

‘We don’t have much time, so let’s focus on improvements.’

Jeong-woo opened the refrigerated facility where catalyst compounds were stored and thought about a combination that could adsorb common hazardous substances that came to mind.

‘Acids, bases, volatile organic compounds, carcinogens, odor-causing components…’

Every five seconds, Jeong-woo mechanically mixed reagents and prepared the catalyst for the filter. As he returned to the table, where he observed this process, Ha Won-il’s eyes widened.

“Mr. Jeong-woo, what you’re doing now…”

“Oh, this combination is temporary. I’ll find a more sophisticated one later.”

After applying the catalyst to the filter, Jeong-woo sent a cloud of dust to help it penetrate better.

“It’s done. Here you go.”

Jeong-woo handed the filter to Ha Won-il, who inserted it into the model house’s connection point for sealing.

Ten minutes later, Jeong-woo and Ha Won-il returned to the integrated inspection room, where sensor measurements to detect pollutants were in full swing.

『Formaldehyde 3.31㏙, Toluene 2.87㏙, Hydrogen Sulfide…』

Significant atmospheric pollutants were detected and displayed on the monitor, with the most critical fine dust reading at ’89㎍/㎥.’

Jeong-woo nodded in agreement while inspecting the inside of the glass through his actual molecular vision. The accuracy appeared nearly error-free when calculated proportionally.

Kim Tae-san quietly observed the results without commenting.

‘Is the sensor team’s measurement capability trustworthy?’

As Jeong-woo was about to shift his focus away from the molecular world, he noticed something conspicuous.

In the area where an external fan was running to create the simulated atmosphere, heavy lead particles were clustering.

According to the sensor readings, due to this phenomenon, the lead content was reported as ‘0.4㎍/㎥,’ which was considered normal.

Feeling the need to address the issue, Jeong-woo raised his hand without hesitation.

『I have a question.』

Amid the silence, Mei’s gaze sharpened as Jeong-woo spoke.

『If pollutants are clustered in one part of the atmosphere, how should we detect them?』

In response to Jeong-woo’s question, Mei said.

『The air circulates. We only need to detect incoming air.』

『But what if a specific pollutant suddenly… Ah, it was around 0.4 micrograms and suddenly jumps to 10 or 20? Can our filter handle that?』

『What are you talking about? Are you saying someone is spreading toxic gas in the building?』

As Jeong-woo watched the monitor, he gently guided some dust particles toward the area where the model house was located.

Free electrons pierced through the glass roof and touched the dust that had gathered near the fan.

Lead dust was drawn into the model house.

Beeep.

An alarm sounded, and the sensor recorded a lead content of ’15㎍/㎥.’

『Exactly like this. This is a very serious atmospheric pollution situation.』

Not only Mei but also the sensor team researchers stared at the monitor with astonishment.

The lead particle dust swirled inside the building and then quickly dissipated into the atmosphere.

The lead content was fixed at ‘0.9㎍/㎥,’ slightly higher than the initial contamination level.

『This is a sensor error?』

『No, it’s not. It appears that the lead content solidified outside the sensor’s detection range.』

Mei’s gaze turned to Jeong-woo as the researchers analyzed the situation.

『How…』

In response to Mei’s inquiry about how he had managed to pinpoint the situation more accurately than the sophisticated sensor, Jeong-woo shook his head.

『Oh, it was just a question. It seems like the situation coincidentally overlapped.』

Jeong-woo smiled coolly and stepped back. While Mei observed him, she continued.

『We need to narrow down the detection angle of the external sensors. That was a good point.』

Before Jeong-woo could react to the unexpected praise, Mei continued speaking.

『The solution is to extend the time for the sensor’s detection range to respond to sudden high influxes of pollutants. If such a situation arises, the AI will analyze it and activate the auxiliary filter.』

『So there is a contingency plan.』

『No.』

『What?』

『We haven’t even started research on auxiliary filters in the filter team.』

Kim Tae-san frowned at the mention of just having ideas without actual progress.

“Team leader Yu, sets the bar too high, which is why it takes so much time for the main filter.”

Ignoring Mei’s cold stare, Kim Tae-san said.

『Team Leader Yu, let’s measure the filters. It’s almost break time.』

After the sensor measurements were completed, the filter device began to be installed in the model house. Jeong-woo hoped that by connecting the bypass device, the trust between the filter team, Mei, and them would increase slightly.

Once preparations were finished, Mei instructed.

『Introduce the pollutants.』

Air filled with contaminants was injected into the sealed model house with a glass roof. The sensors on the monitor immediately lit up with red warning lights.

『Prepare to start the fan. One, two… three!』

With a whooshing sound, the air purification system was activated.

The readings on the monitor initially fluctuated but gradually changed from red to yellow and then to green.

“Look, our filter. It’s doing it in just 10 seconds.”

In response to Kim Tae-san’s muttered comment, the entire filter team nodded in satisfaction.

Mei carefully examined the displayed pollutant levels and said.

『The detection rate for bacteria is higher than the previous test.』

『Still within the safe range, right?』

『For bacteria, viruses, and volatile organic compounds related to respiratory diseases, the lower the detection rate, the better.』

『No, Team Leader Yu. Go outside adn see if you can you breathe better air than this.』

Jeong-woo felt the pressure of Mei and Kim Tae-san’s ongoing dispute. He quietly asked Ha Won-il.

“Do they ever have days when they don’t fight?”

“I’ve been on this project for a month now, and I’ve only seen it happen once.”

“When was that?”

“Kim Tae-san, the lead researcher, took a day off.”

Jeong-woo took comfort in the fact that it was quite rare for Korean researchers in this room to get along. Building better relationships was not an easy task for anyone.

Senior researcher Jun Chai from the sensor team, who had been closely monitoring the monitor, suddenly called Mei.

『Team Leader, the measurements for Room 10 are abnormal.』

Mei shifted her gaze to the monitor upon hearing this. The various contamination levels in Room 10 were noticeably lower than in other areas.

Kim Tae-san, also noticing this, was surprised and mumbled.

“What’s going on? This is the area with the lowest airflow. It should be higher, why is it like this? Is it a sensor error?”

Ha Won-il responded in a low voice.

“Mr. Jeong-woo attached the bypass filter.”

“What?”

Mei, along with Jun Chai, meticulously checked the readings for Room 10 and then spoke to Kim Tae-sanjosei

『This room has a cleanliness level equivalent to a Grade 6 cleanroom for newborns. Excellent improvement. Please continue to work like this.』

Kim Tae-san, who had received praise for the first time since the project began, had an awkward expression on his face. Although he didn’t particularly like Mei’s personality, which shifted from arguing loudly to giving high praise, Kim Tae-san refrained from speaking ill of her in Korean.

Jeong-woo felt a sense of relief, sensing that the atmosphere was getting less tense.

‘Is this going according to plan?’

He thought about Noh Jong-seon’s suggestion to help the project with 0.5 points every day as it was a project that lacked 20 points to reach a perfect score out of 100.

After the measurements in the Integrated Testing Laboratory were completed, it was time to leave for the day. As Ha Won-il headed outside, he spoke to Jeong-woo.

“Having you here really puts my mind at ease. I think I can learn a lot.”

“I’ll do my best for the next three weeks.”

“It’s my turn to say that.”

With a polite nod, Ha Won-il disappeared, and Jeong-woo turned to leave for the day. However, he unexpectedly found himself facing Mei, who was observing him.

‘Oh, what a surprise.’

Mei opened her mouth to speak to Jeong-woo.

『Mr. Han.』

『Yes.』

『I said that there’s no one who can do everything well. Do you disagree with my statement?』

Confidence or humility? Two options that Jeong-woo had been regretting in the morning floated through his mind.

『I’m not sure about that. However, as long as my abilities allow, I will do my best to assist Team Leader Yu. Research is not something you do alone.』

Mei, who was scrutinizing Jeong-woo, spoke.

『I look forward to your continued contributions, just like the bypass filter.』

It seems like she knows that I was the one who wrote it.

『As the team leader, I have one thing to tell the assistant team leader. This project must succeed no matter what. In that sense, Professor Noh Jong-seon and Researcher Ha Won-il trust you, and we have high expectations for you.』

Mei, now officially designated as the assistant team leader, extended her hand. Jeong-woo nodded and accepted her handshake.

Dosandaero, Gangnam-gu, Starpiece Building.

Jeong-woo stepped out of the taxi and looked at the five-story building surrounded by subtle lighting.

As befitting an entertainment company building, it had a distinct design that stood out from the neighboring buildings.

A photo on the rooftop LED display caught his eye.

It was a photo of a hotel room with a view of Venice’s scenery from the window. Yoon Yi-seol, with a dazed expression, holding a guitar.

Her slightly disheveled hair on one side, and her unusually fair skin gleamed.

‘She looks cute like that. Pretty…’

Given that professionals took the photo, it was clear that they aimed for a concept that would make fans’ hearts flutter. There was text next to the picture.

【Yoon Yi-seol’s Single Album ‘In a dream’ / Release on March 26th!】

‘What kind of song is it? It must be good, of course.’

As he stared at her in the large photo, memories of that day on the beach came vividly to his mind.

How could he forget it? The beautiful woman on the billboard had written such a heartfelt letter and even kissed him on the lips. Thinking about it made him sigh.

‘I managed to come this far, but what am I supposed to do Dr. Moon?’

Standing in front of the automatic door at the entrance, Jeong-woo sent a text message to Yoon Yi-seol.

[I’ve arrived.]

A prompt response followed.

[2nd floor practice room.]

A short, emotionless message. It had been like this all day, starting from lunch. Jeong-woo sighed at her response, not even knowing how angry she might be.

The sliding door opened from the inside, and Jeong-woo took a tentative step inside and said awkwardly.

“Excuse me.”

The exterior of the building might look like a music studio, but inside, there was a cozy space with a musical ambiance, complete with signs bearing musical notes on rooms like editing studios and recording rooms. At the far end, he could see a staircase.

“It has a unique design for Yoon Yi-seol.”

“Yes, that’s the concept.”

As Jeong-woo mumbled to himself, someone’s voice reached his ears.

“Welcome, Mr. Han Jeong-woo.”

He turned to find Manager Ji Seong-jae. Seated at a table in the music cafe-like space, he greeted Jeong-woo.

“If you’re not too busy, can we chat for a moment before going upstairs?”

“Yi-seol is waiting upstairs…”

“It’s about Yi-seol. She asked me to delay you for a bit.”

“I see.”

Once Jeong-woo took a seat, Manager Ji poured a glass of water for him.

“You don’t drink coffee, right? That’s what I heard.”

“Yes, this is fine.”

Jeong-woo took a sip of water, and Manager Ji watched him silently before speaking.

To be honest, until recently, I was just grateful to you, Han Jeong-woo. After going to the clinic, Yi-seol has become much brighter.”

“Right now, it doesn’t seem that way, though. Haha.”

While Jeong-woo awkwardly laughed, Manager Ji’s expression remained solemn.

“What’s confusing is that, despite the fact that it’s a time for joy, our singer has been holed up there for a week, making excuses and behaving irritably under the pretext of preparing for a showcase.”

“Um… I see…”

Though Jeong-woo tried to deflect the conversation, Manager Ji seemed to have sensed something.

“I think Yi-seol did something to you, according to what I saw.”

Manager Ji’s fingertip made the heart-patterned teaspoon in the cup bounce.

“Han Jeong-woo rejected whatever that something was.”

In response to Manager Ji’s questioning look, Jeong-woo could only smile wordlessly. Why would he refuse the advances of a charismatic megastar that the whole nation admired?

“Let me ask you directly. Do you not find Yi-seol attractive?”

“She’s beautiful. Extremely so. However, there are circumstances I can’t reveal.”

Detecting a hint of bitterness in Jeong-woo’s smile, Manager Ji continued.

“I don’t understand why you’re making it so complicated. If it’s about self-esteem related to that matter, think again. Can there really be a man in South Korea who wouldn be deemed worthy? No matter who pursues her, they all fall short.”

“You’ve hit the nail on the head.”

“It’s been over five years since I got married, and my dating cells are practically dead. But when I listen to Yi-seol’s songs, there are moments when my heart flutters. Especially with this new song. Is there any special meaning to liking someone? Just follow your heart.”

As Manager Ji passionately spoke, there was an urgent sound of footsteps from the second-floor staircase.

Thud, thud, thud!

“Manager!”

Yoon Yi-seol, who suddenly appeared, took a deep breath and glared at Manager Ji.

“What are you doing with Jeong-woo?”

“Um, I was passing by, and he looked thirsty, so I offered him some water.”

Jeong-woo was surprised by this response, and he looked at Manager Ji.

Manager Ji, avoiding eye contact, gestured to Jeong-woo to leave, then turned away from Yoon Yi-seol.

Only then did Jeong-woo realize that she hadn’t asked him to delay his arrival.

“Ugh, really.”

Yoon Yi-seol looked at Jeong-woo once and then lowered her head.

“Come up! Right now!”

And she ran up the stairs and disappeared. Jeong-woo asked Manager Ji, pointing to the corridor she had just dashed down.

“Has Yi-seol been like this recently?”

“Even more so. Today, she had an angelic attitude because it’s Han Jeong-woo’s visit day.”

“I see…”

With a fearful heart, Jeong-woo headed to the second-floor practice room.

Click.

Jeong-woo opened the door and saw Yoon Yi-seol sitting in a chair, holding a guitar. She looked at him as he entered.

Jeong-woo greeted her cautiously.

“It’s been a while…”

“That’s enough. The contract is on the desk. You need to sign it to give the road manager team their pay. That’s why I called you, so don’t misunderstand.”

“Okay…”

“And well, now, I don’t plan to take any interest in you. But if you still have a bit of affection as a fan, you can listen to the new song before you go.”

Without giving Jeong-woo a chance to reply, Yoon Yi-seol continued to speak in a rushed manner, her fingers nervously tapping the guitar body, as if she were anxious about his reaction.

It was the same old her, with her emotions plain on her face.

‘Ugh. I thought I had already finished sorting things out.’

Jeong-woo sat down and said.

“I will sign the contract since it takes me a long time to do so. I’ll sit for a while.”

Yoon Yi-seol’s expression shifted to relief, “Sure, go ahead” as she turned her head politely. After clearing her throat, she put her hand on the guitar.

Strum.

The gentle melody of the guitar blended with Yoon Yi-seol’s voice.

-I’ve fallen for you.

Her hair fluttered lightly against the guitar’s body, and Jeong-woo twitched as he heard the first line.

The lyrics from the notebook he had seen on that beach that day, written in her handwriting, were now a song being sung through her.

-This morning. Since when was it a dream? The magical moments keep coming back, and I can’t wake up.

For three minutes, Yoon Yi-seol’s genuine emotions were conveyed through the serene melody and heartfelt lyrics. The love cells in Jeong-woo’s heart, which had been deeply buried, began to tremble.

-I want to keep seeing you. I close my eyes again. I feel like I’ll see you on days like this. Goodnight, my love. I’ll see you again…

The chorus of the second verse ended.

Jeong-woo looked at Yoon Yi-seol, unable to say anything.

Her beautiful voice and the sincerity it carried.

Who could resist such a confession from the bottom of one’s heart? Jeong-woo couldn’t help but strongly empathize with Manager Ji’s words, “Can there really be a man in South Korea who wouldn be deemed worthy? No matter who pursues her, they all fall short.”

“Is the signing done?”

When Yoon Yi-seol finished the song, Jeong-woo, who had snapped out of his trance, automatically signed the contract and then turned to her.

“This song is really good.”

“What about me?”

“What?”

“How much do you like me?”

When did it become like this, with his heart racing and questions flying around uncontrollably? Jeong-woo couldn’t help but wonder if it was even possible for a person to survive with their heart pounding like this.

While Jeong-woo hesitated to answer, Yoon Yi-seol, who had noticed said.

“The next thing you’ll say is about waiting ten months, right? Okay, go now.”

“Yi-seol…”

Jeong-woo stood up and asked.

“Is there anything bothering you?”

“Why would you be curious about that? Weren’t you just here to sign the contract and leave?”

Seeing Yoon Yi-seol’s resolute expression, Jeong-woo had no choice but to head towards the door. Going to the hospital together is just a crazy idea right now. As long as she looks fine on the outside, that’s a relief in itself.

‘I need to find another way.’

As Jeong-woo touched the door handle, Yoon Yi-seol spoke as if she had been waiting for him.

“By any chance…”

Jeong-woo’s steps halted.

“I only have seven items left on my checklist, and I just did one with you today. The rest are also planned with you. If you don’t like it, you can say so now.”

“I don’t dislike it… but what did we do today?”

“I gave someone who used to bother me a piece of my mind.”

“It seems like you really gave them a piece of your mind”

Yoon Yi-seol, with a teasing smile, replied to Jeong-woo.

“It’s not over yet. I haven’t even hit them yet.”

“Are you really going to hit them?”

Yoon Yi-seol looked surprised, and Jeong-woo chuckled.

“A commercial request came in. From the company where you work.”

“That’s…”

“I accepted it with one condition. How about appearing as a couple? The person in charge, Manager Cha Jin-seong, liked the idea”

Jeong-woo’s expression went blank.

“A couple? I’ve never acted before. Yi-seol, you know that.”

“So, yeah. I’m going to doll myself up that day, so be prepared to be thoroughly impressed.”

With a thud, Jeong-woo stepped into the corridor with a dazed look.

How many unexpected things had happened to him today? At this point, he couldn’t even count the number.

“Hoo.”

Yoon Yi-seol pressed her ear to the door, listening for the fading footsteps she let out a sigh of relief.

A live performance with all her might.

If she sang like this every day, she might have twice as many fans. Even though it was just one song, her legs were trembling.

She sat down on the floor and leaned against the door.

“Do you think I did well?”

Her face showed signs of absent-mindedness and a wavering heart. She was sure of that.

“Be prepared to keep liking me in the future.”

Yoon Yi-seol held her arms around herself, drawing a happy smile. In matters of love, she had to be more proactive, it hurt less that way.

If two-way traffic is difficult, you can just break through an eight-lane highway from one side to keep going.