"Is it alright if I take a nap?" Yerin asked as soon as they entered Hyunjae's house. 

He looked at her, concern building up in him again. She looked pale and kept rubbing her temple, as though her headache wouldn't go away. 

"Of course," he told her. "I'll put clean bedsheets in my room. You can take my bed, I'll sleep on the sofa." 

She nodded, looking unsurprised. "Thank you," she whispered, dropping the two items she came with onto the table before heading to his room. 

The only two items she had.

He stopped, staring at the items for a moment before following her. What a mysterious girl she was. 

She popped out of nowhere and said the craziest things. He was certain that they had never met before, and yet her face showed recognition when she'd seen him and Hyewon. 

When he walked into his room, he was surprised to see that she'd already taken the old sheets off of his bed and had put them into the wash basket. He watched in confusion as she walked over to his dresser, opening the right drawer on the first try, and taking out the new bedsheets. 

"How'd you know they were in that drawer?" he asked, trying to sound casual. Maybe this girl was his stalker or something. Maybe that's why she'd looked at him with recognition. But no, she'd tried to get away from him. She'd acted hysterically when he tried to reach out to her. If she'd been his stalker, why would she act that way? 

"Just a hunch," she said softly as she started to make the bed, her eyes lost in thought. 

"Here," he told her, opening the drawer where he kept his pajamas and tossing a shirt to her. "Change into something clean. Would you prefer wearing shorts or long pants?" 

"Shorts please," she said, her voice growing weaker by the second. When he walked over to give her the shorts, he noticed she was shaking. 

"Will these fit me?" she said, her voice an attempt at teasing. 

"They're elastic... so hopefully?" he told her, giving her a smile. She smiled back in return, but it didn't quite meet her eyes. 

"Thanks," she mumbled, taking the clothes and heading to the bathroom to change. By the time she came out, he'd finished making the bed and had managed to tidy up his room a bit more.

Her eyes were red as if she'd been crying in there, and he felt a pang of worry. 

Yerin didn't even look at him as she came back into the room, she just hopped into bed and pulled the covers up to her chin, all the while mumbling something about "trying to wake up."

Hyunjae turned off the lights and left the room, hoping that she'd be able to get some rest. Maybe when she woke up she'd feel better. Maybe then she'd remember some helpful information about herself. 

He walked over to the table and picked up her ID card. Kim Yerin. Her name felt familiar, and yet he was certain that he'd never seen her before. But then where had he heard her name? Why was it familiar to him?

Though he felt a pang of guilt as he did so, he took his phone out and took pictures of her two belongings. 

And then he sent them to Sangyeon. 

It took less than a minute for his phone to ring. 

"What do you want me to do with these, exactly?" Sangyeon asked from over the phone. 

"You're a detective, so what do you think I want you to do?" Hyunjae replied, trying to make his voice sound light and teasing. "There's something different about her," he said, his voice taking on a serious tone as he looked at his room door. "She just appeared at the school. I know that I haven't met everyone who goes to school there... but she seems so lost. She keeps saying strange things. There's just something different. Can you please help me?" 

A pause. Then, "who do you think she is?"

"I have no idea," Hyunjae sighed. "She doesn't seem like a bad person though, if that's what you mean. She just seems... lost." 

"I'll look into it for you," Sangyeon said after a moment. "But it may take a while." 

"That's okay," Hyunjae said gratefully. "Thank you. Thank you so much." 

He hung up and placed his phone on the table, his eyes going back to his room door. "Who are you?" He whispered. "You mysterious girl... who are you exactly?"