Wonwoo walked into their cyber lab one morning, finding someone else seated on Eunhye's computer station. He met eyes with Mark Tuan, who took a quick look at him from head to toe. One other person was surprised not to see their usual TA. Sana almost did not go inside the room but her friend, Momo pushed her through the door.

"Eunhye-sunbaenim was out sick," Mark said when all of the students were in. "I will take over until she gets back She did say you were still working on the last activity she gave you so you can continue doing that now."

The girl never told Wonwoo anything. He wanted to ask her how she was after the last couple of days. The last time he saw her was when she was heaving with Chanyeol beside her. He also meant to ask Eunhye about the...symptoms she had been having the past week.

"Sunbaenim," he said, raising his hand to get Mark's attention. "I'm actually done with the activity last week. Can I go ahead?"

"Perfect," Mark said. "You can start on the next one, then." The guy directed him to another folder where a new set of instructions were. "Same for the others."

Wonwoo almost thought the guy made a special activity for him. Another student, Im Changkyun was also done with the previous week's activity and was starting on the same module as him. On their internal chatroom, some of the girls were commenting on how good looking their new TA was.

Joy: I like Eunhye-sunbae but u gotta admit. Mark-sunbae is hot.
Momo: He is, sure.
Hanbin: Eunhye-sunbae's hotter.
Changkyun: hahaha.
Changkyun: i thought u'd agree with the girls, B.I
Hanbin: Dude, shush.
Joy: Mark-sunbae's not even doing anything.
Joy: U guys should try to be more like him.
Changkyun: like what? not do anything?
Momo: I wish Chanyeol-sunbae took over, though. He's funny.
Soonyoung: I can make you laugh, Momo.

Wonwoo turned to look at what Sana was doing while this was happening. Her eyes were fixated somewhere else far from the computer to care what they were talking about. He wondered who chose Mark to take over the class in Eunhye's absence. He doubted it was her. She had enough sense not to put Sana and the guy in one room.

Or maybe she did.

Taking his phone out, he texted her.

Wonwoo: Where are you?

He went back to his computer, but his phone vibrated as she replied. He actually did not expect one, but there it was. One word.

Hye.Noona: Home.

Wonwoo typed quickly. He had a feeling if their sub TA would see him, he was going to get word.

Wonwoo: Are u ok? 
Wonwoo: Why is ur EX taking over ur class?
Hye.Noona: What?!
Hye.Noona: Why him?
Hye.Noona: I told L to take over.
Hye.Noona: What is sana doing?
Wonwoo: Looking like Olaf in summer.

He finally confirmed that her messaging app was working, but then she stopped replying again. It showed that she read the message. He stared at his phone for another two minutes and then gave up, putting it back in his pocket before Mark saw him. He should just finish quickly and leave.

"Dude, you're smiling like an idiot," Soonyoung told him. "Don't get cocky that you're one activity ahead."

*********

"L?" Eunhye barged into the TA Room only to find Chanyeol alone, playing a mobile game. 

"I thought you're out sick?" Chanyeol asked. "How's the stomach?"

"Where's Kim Myungsoo?"

Chanyeol shrugged. "I just came back from a class. Why do you look so scary so early in the day? PMS?"

"Who made Tuan take over my class?"

Lee Minhyuk, another TA from Mark's class came in just in time to hear her question. "Him and L-sunbae are the only ones vacant this morning."

"What's the emergency?" Chanyeol asked.

Eunhye came closer to him so only he could hear. "Sana's in my class."

"Oh? It was her you're worried about?"

She hit his shoulder. "Ya. Next time, tell me these things so I can come here instead."

"You were out sick. How was I to know you were just faking it?"

"I'm not faking it," she snapped. She just got a bit surprised at the little news Wonwoo  had for her that morning. It was also a good excuse to go there. "When Myungsoo gets back tell him... Never mind. I'll call him later."

Chanyeol got up. "Are you going home? Let's go. I'll drive you there."

They were on their way out when Mark came in. "You're here?"

"Did you lock Lab 17?" she asked. Mark handed her the key. Without another word, Eunhye went on ahead. Chanyeol had to run to keep up with her.

"That was not awkward at all," he said sarcastically.

She gave the key to Chanyeol. "I don't want him near my lab."

"Aye, sir." Chanyeol was whistling all the way to the parking lot. They got on the huge car he had. "So how did you know it was Mark who took over your class?"

"A hoobae told me."

"That hoobae?" Chanyeol pointed at someone exiting the school's south gate where they passed. He honked the horn, making Wonwoo and Soonyoung turn. The two bowed in greeting