When Dowook opened the door of Room 2007, he saw Lim So Yool boiling water in an electric pot.

"Director."

"Youre here."

Lim So Yool, holding a tea bag in her hand, made eye contact with Dowook.

"Would you like some? Or coffee?

"Coffee sounds good.

Lim So Yool opened all the cupboards in the reception room and found a container containing coffee. Dowook approached to help her open the lid since she was having trouble with it.

"I"

"Huh?"

Even before finishing her sentence, the container slipped from her hand. Coincidentally, Dowook naturally snatched it away. While he was holding it, he opened the lid and held it out.

"Here."

"Oh, thank you."

Lim So Yool, who was already scooping some coffee out, jerked her head up.

"Did you think I'd make a mistake?"

"It was a coincidence."

"Coincidence is part of the probability. If you had predicted my usual pattern, it means that I've been acting that poorly. There was only one time when I dropped something absurdly in front of the doctor, ok?

The switch of the electric pot went up, and Lim So Yool, who started pouring water, jerked back to look at Dowook. Then she carefully adjusted the amount of water as if she would never make a mistake.

Dowook smirked.

"Isn't life too tight if you try to figure out how coincidental everything around you is?"

"Even if you calculate the exact time of sunrise, the wonder of the sunrise across the horizon can not impaired."

"That's impressive."

"It's not a good counter argument to show that understanding the world with probability is fine. Here, coffee."

"Thank you."

Dowook took the mug and moved to the hospital room that now ambiguously resembled a residential and office room.

Sitting face to face with Lim So Yool at the table, he presented a photo of Detective Yoons notebook on his cell phone.

"This is the encryption sequence I told you about.

Lim So Yool, who took a sip of the sweet-smelling herbal tea, asked while looking at the screen with interest.

"This patient must be a unique case. Youre bringing something like this over. What are you helping with?

"Its not a patient."

Lim So Yool's gaze became sharp at his response.

"Its not even a patient, but you're calculating like this?"

She seemed a little angry, and Dowook looked at her, Huh?' he couldn't judge how she felt right now just by her expression.

"We didn't calculate together, we investigated together.

"Investigate?

A major accident occurred, and detectives and criminals were brought to the hospital together, and one of them was operated on and even helped with this.

After hearing it all, Lim So Yool lifted her notebook and pen with a relieved look.

"Oh, it's fine. But you overpowered a person twice?

"I'm not exaggerating."

"I think that's possible. Because its you."

Lim So Yool, who expressed her belief, handed a pen to Dowook.

"Should we begin calculating?

"Let's do it."

Dowook placed his cell phone on the table and turned on the screen.

"How do you solve this code?"

"We need coincidence."

"What?"

Lim So Yool smiled at the bewildered expression on Dowooks face.

"One-way functions are useful to hide numbers so that only I can recognize them. Usually, we use a small number."

A snooty number that only decomposes into one with oneself, a prime number, one of which was written on the note of Lim So Yool.

"The code that the doctor brought can be expressed one by one in an equation containing a few. It's entirely up to the mathematician's intuition to understand the 54 riddles in numbers. That's why we need coincidence.

Lim So Yool, who opened her notebook, looked at Dowook.

"Let's start with Equation. I'll start from the front. You from the back."

Dowook felt Lim So Yool's sense rushing into his hands. This impulse alone could tell him that she was excited about the challenge ahead of them.

Wiggling fingers.

These days, he felt very sensitive about accepting other peoples senses.

"How many days until the director's sense reaches 100%?

A different feeling from the familiarity of medical science. Dowook thought he would only know how much proficiency he could build after overcoming this unfamiliarity.

"Let's get started."

The room became quiet for a while. Only the crunching of paper, scribbling of writing and sipping of drinks could be heard in the silence.

After about 10 minutes, the equations of the two overlapped in the 30th string.

Lim So Yool's pen, which was fiercely continuing her writing, stopped. And she looked at the tip of Dowooks pen.

"You only did 24. You can do the one left."

"I'll give it to you. I lost anyway."

"Haha."

The last equation was recorded, and Lim So Yool, who went through the results, began organizing it on a new page.

"These are all the numbers before encryption.

Dowook confirmed that the number estimated as the account number and the number estimated as the IP address were clearly revealed and realized that Sergeant Ham's prediction was correct.

"Thank you, director. This will become a clue.

"I hope you catch the criminal.

Dowook, who was in a hurry to deliver it to Detective Yoon, waved lightly to Lim So Yool as a good-bye.

Bowing his head slightly before leaving, Dowook looked over her shoulders, and the spacious room behind her caught his eye.

The scenery of sitting alone next to the table looked very lonely.

"These days, I feel like I'm asking you for too many favors. Is there anything you want to ask of me?"

"Will you listen to anything?"

"Yes."

Lim So Yool answered after thinking for a moment.

"Then please go somewhere with me."

"Oka Huh? Where do you want to go? It's not calculating something complicated?

"It'd be better if you came and calculated with me as well."

Dowook thought it wouldn't be a simple place, but once she spoke up, he nodded.

"Please contact me when the time is set. I'll make sure to leave my schedule empty."

Ill look forward to it.

Dowook came out, walked to the entrance of the VIP ward and saw two large men standing upright. In front of them, two police officers in working clothes were also standing together.

There had been no invisible threats since the fake intern incident, but there were currently four people following him for protection.

"Shall we go?"

While walking in the elevator with four followers, Muk-ho asked.

"Are you done, doctor?"

Dowook shook the paper in his hand.

"It just came out."

"The bastard who did this to our Sung-oh hyung-nim. I hope that you catch him and put him behind the bars. He even called the people over cheaply.

Muk-ho, who tried to recruit him and Choi Hoo, excitedly bit and tore the criminal with a very generous mind.

"Copper, don't you think so? A crazy kid who blows up a building just because he's in trouble. He should be fed a lot of bean rice."

[T/N: The bean rice comment is referring to jail since its widely considered that food in jail is so bad/cheap that they dont even give you rice but mix it with beans.]

"That's "

Those police officers could not treat the two men as if they were children like Detective Yoon. They were quite simple once you got to know them but Dowook could not tell them that.

They took the elevator and got off on the first floor where the emergency room was located.

Ding.

"Huh?"

Muk-ho's speech decreased sharply because Detective Yoon and other detectives in plain clothes were gathered in one place near the emergency room entrance.

As he approached, he found a man in his 50s standing among the detectives and shouting angrily.

-Hey, Yoon Joong-gi! What are you doing? If you're going to use the forensics, you have to report it. Are you the only one investigating?

-Captain Oh, you said you were going to focus on interrogating the criminal..

-Look at this guys sly mouth. You were trying not to spit out important evidence!

Detective Yoon was being badly scolded by Captain Oh.

-No, the evidence is in this notebook.

-You said your laptop was stolen! Get rid of useless things right now!

Captain Oh hit the notebook and it flew in the air until it fell in front of Dowooks foot.

Dowook picked up the notebook and approached.

"Umm"

Captain Oh glanced at the doctor who appeared with a gangster and police officer on his back at the same time. While trying to turn his head toward Officer Yoon again, he looked at Dowook again because the composition of the personnel was unique.

"Who are you?"

When Dowook met Captain Oh, he was reminded of the face of the integrated internal medicine chief, who had been making noise while finding fault in him not long ago.

Dowook didn't know if a selfish number was included in the police's struggle for power, but the intensity of pressure seemed no different from the doctor's society.

"Who are you? We're conducting an important investigation. If you're going to interrupt.

"This notebook."

Dowook turned to Officer Yoon, who was isolated alone. And he continued to talk.

"With the information written on this notebook, I found the account number and IP address that the criminal used for the first deposit. This person says it's useless. What about you, Officer Yoon? Do you need it?

All of the first-tier detectives in the metropolitan area, including Captain Oh, had widened their eyes.

Detective Yoon asked with a surprised face.

"Did you really find it?"

"Here you go."

Detective Yoon's face, as he received the paper written by Lim So Yool, was in full bloom. Detective Yoon immediately picked up his cell phone and called Lieutenant Ahn Seok-young at the headquarters.

"Detective Ahn, please start the account tracking. Sergeant Ham will be in the cyber team office. Yes, it's suspected to be the criminal's account."

Captain Oh approached Officer Yoon, who asked for tracking quickly.

"What are you doing now? That person is. Oh, I'm stammering. What are you two doing right now?

"We're conducting a joint investigation."

"You have to report it to me."

Detective Yoon stood next to Dowook and answered firmly.

"We are not obligated to report confidential cooperative investigations with outsiders until the end."

"Where is the principle. Whos he? Why does he have gangsters next to him?

"This is the person who caught the bomber of the cafe. Hes Park Dowook from the hospital."

Captain Oh looked dumbfounded by this answer. Muk-ho, who was behind Dowook, intervened tactlessly.

"That's right, detectives. I definitely saw it. The doctor hit the player's chin with his fist! Oh, well. The police missed the guy from the lottery tickets, but the doctor hit him! Put it on the floor with a piggyback throw.

No one could stop Muk-ho, who opened his mouth, because it was such an amazing situation that the doctor did everything in a place full of detectives and police.

Vrrrr.

In the meantime, Detective Yoon's cell phone rang.

Background check information from the headquarters tracking account numbers and IP addresses came in one after another.

Graduation photo of a man wearing a graduation cap from 10 years ago.

A graduate of computer science at KAIST.

CEO of an IT company currently suspected of being a paper company.

It was the perfect match for Heogi-poong-gi profile created by Captain Cheon while holding onto the computer until dawn for six months.

Detective Yoon looked at Captain Oh.

"Among the emergency room investigators, is there a man whose name is Seo Jung Chul? In his early to mid-30s."

"I think I heard it. That's right. The man wearing the baseball cap was Seo Jung-chul."

"That guy is Heogi-poong."

Finally, they succeeded in identifying the suspect.

As soon as Detective Yoon's words were over, the first-tier detectives rushed to the emergency room.

Seo Jung-chul, who was waiting in front of the X-ray room, sensed that the entire atmosphere in the emergency room was unusual, with nearby police busy talking on the radio.

He didn't think they would have caught him.

Far away, a detective was seen looking at the bed he was lying on. When the medical staff pointed their fingers at the direction of the X-ray room, Seo Jung-chul immediately stuck his body behind the wall.

It seemed like he was caught.

Seo Jung-chul pulled out the IV stuck in his arm.

"Patient, if you do that"

He put the hat on the doctor's head standing in front of him and ran to the emergency exit.

Hed familiarized himself with the internal structure of the building in advance.

Next to the indoor garden on the third floor, there was an overpass that led to the building across from it.

If he passed there and ran toward the medical school campus, he would be able to buy time.

Seo Jung-chul ran fast and put his cell phone to his ear.

"Where are you guys? If you want to get the balance, be quick! The building across from the main building! Come and buy me time!!"

It was the moment he opened the emergency exit door on the third floor and ran to the hallway of the indoor garden. Someone jumped next to him and tackled him.

Crash!

The opponent, who caused Soe Jung-chul to lose his balance and fall, held him so he could not move and said.

"Seo Jeong-cheol, youre under arrest on charges of violating illegal fund management, special violence, and concealment of criminal proceeds. You have the right to appoint a lawyer, make excuses, and exercise your right to remain silent. However, confessing everything and asking for leniency will be the way to reduce the sentence. We've got the evidence for the crime.

"What are you"

"Oh, you're talking too casually. Then me too. Im Lieutenant Yoon Joong-gi. I came from the Investigation Team to catch a big shot. I can't believe I handcuffed a guy like you. It's an honor, Heogi-poong."

Seo Jung-chul, who was caught motionlessly, gritted his teeth.