Si Xing and Kim Jae-In made their way to the security room. The school security guard was reluctant at first, but a stern look from Jae-In made him comply.

Si Xing fast-forwarded through the footage. "Here, look. Aina is going up the stairs. She's alone."

Kim Jae-In squinted at the screen. "Wait, pause. Who's that following her?"

They watched as a shadowy figure appeared on the stairs, moments after Aina.

Li Yun studied the security footage, his eyes narrowing as he pieced together the events leading to clues. The camera near the roof entrance revealed crucial details:

Aina's Entrance: At precisely 8:45 PM, Aina stepped into the roof. Her expression was unreadable, her footsteps echoing in the space. But there was no footage of her leaving.

The Hooded Figure: Five minutes later, at 8:50 PM, another figure appeared—a shadowy silhouette in a hoodie. They followed Aina, their movements deliberate. Who were they, and what was their connection to her?

And another thing was found.

At 9:00 PM, the school janitor entered the Roof. His presence seemed routine, but Li Yun’s instincts prickled. Why would a janitor visit this secluded spot? And why did he leave after just five minutes?

At this time Kim Woojin also handed over the results concluded after looking at the cell phone records.

Si Xing also looked at the sheet and frowned.

Li Yun turned his attention to the cell phone records. The digital trail held its own secrets:

At 8:30 PM, Emily received a call from an unknown number. Five minutes—a conversation that could change everything. But who was on the other end, and what did they discuss?

"Who do you think would call her?"

Si Xing mumbled.

"Her boyfriend?"

Li Yun paused. Yes, girls this age easily fall in love.

Kim Woojin sighed and said.

"The number traced back to a disposable phone, purchased earlier that day. I don't think a boy this age will use so many brain cells."

Kim Jae-In scratched his head, He wouldn't even if others did.

Li Yun closed the book.

"It's already evening and students have left. The teaching faculty will leave in a while too. I don't think we will get any more clues for today."

Everyone agreed that this case was more like a verbal mystery game. They need to gather clues and get to the murderer before the time limit. It was easy if people knew the essence but difficult for those who won't use their brain cell.

That night, Alex and Lisa sneaked inside the investigation room with the help of Ayesha. At the same time, Lin Xueyin and Xie Zhili sneaked them some food.

"It seems that we can't leave the school grounds."

Alex and Lisa nodded and took some snacks from their school bag.

"It's good that Lisa reminded me to grab food in an emergency."

Li Yun appreciated their smart move. 

"Well done. I have tried it but we can't leave the School grounds, it's like it is a boundary and only the original inhabitants can go out unlike us."

Si Xing opened the snack bag and passed it to Li Yun.

"Brother Li, eat something and rest."

Ayesha and Lisa went to the staff washroom to take a bath while Li Yun and Su Mingji took torches and went to check the school library.

"Do you think we will find some information there?"

Su Mingji asked while chewing the gum in a carefree manner.

Li Yun yawned.

"No, I don't so."

Not because of anything but because this is only Floor 2, They need to clear 100 floors and the first few won't be so hard to the point of suffocating people.

However, It wasn't evident.

"There are few victims and none of them are known." Su Mingji expressed.

Li Yun nodded.

"It's best we find who she knew, who her friends were and if she had  found a secret of someone she shouldn't."

Hearing his words as if he was used to these situations, Su Mingji asked.

"Were you a detective?"

It was the sudden but nice question for Li Yun. He enjoyed the word but shook his head and chuckled.

"I was a simple novelist."

Now it was Su Mingji's turn to be shocked.

"Ah?! How come?! You look so...seasoned solider....are all authors like this?"

Li Yun laughed, It was the first time in a long while he enjoyed the situation.

"Who knows, but I am."

The two chatted and searched the library newspaper and they did find something.

There was an article written by a student on illegal relationships of students and teachers. 

"We found a direction, See the name of the student."

Su Mingji pointed at the author's column.

Li Yun nodded.

The two left and shared their discovery with each other.

"Nir-Asha? Wait, isn't it Nir...written backward to Rin?"

Ayesha frowned.

Lisa mumbled. "Poor girl, She must have known about something and couldn't do anything but write it in her article right?"

Xie Zhili also frowned.

"If it's a teacher, Xiao Lin and I will keep an eye."

 Knowing that it was easy for Xie Zhili with his identity to investigate. Li Yun nodded in agreement.

The next morning, Li Yun asked the students around about Rin Aina.

"She was a bit silent."

"I didn't notice her on the normal routine."

"She is always alone. Ah? Why? Because she was an orphan."

"I heard she was a scholarship student and the School's Idol appreciated her."

"The school janitor? He is nice guy."

Li Yun frowned the more he investigated, it was like Rin Aina was not even noticed by her classmates. As if her existence was not considered in this school. So even if she suicides out of depression, that will be normal if he hadn't found that article last night.

So we need to change the direction of investigation.