“So how does double replacement work?” Taehyung asked when he sat next to Wheein. The two of them never really knew how to say hi to each other. If they saw each other in the halls, it was like a challenge had appeared. They were a real odd case. Their dance parties were bound to be on at least twenty people’s Snapchats. It deserved to be on Snapchat. It was fifteen seconds of fabulousness, what wasn't there to love?

Not that it bothered either of them, they really didn’t care what others thought of them. They just liked dance parties in the middle of busy halls. It was only natural to dance. The school was a little too depressing for the both of them. And, if it weren't for dance parties, Wheein would have died of boredom.

So, whenever they were in class together, they had a tendency to be a little more professional. Taehyung couldn’t afford to fail the class and Wheein never got anything below a 90% in the class. Chemistry class was fairly business for the two of them. No one understood why they took forever just to finish their lab though. Honestly, Wheein blamed Taehyung’s disinterest in labs for the reason. Taehyung blamed it on Wonwoo which didn’t make sense because they weren’t even at the same lab bench.

“If A goes to prom with B and C goes to the prom with D, what happens?” Wheein asked as she scribbled the little equation onto her notes.

“A s B and C s D?” Taehyung questioned. Oh right, they were both seniors in high schools and not all guys were going to be like Wonwoo. People actually thought of a lot. She wished all guys were like Wonwoo. They were more bearable that way.

“Have a on you every time you’re out with a girl,” Wheein replied. Wheein never really understood why high school was such a time to have , but she didn’t want to question it. It would warp her sense of reality and she would be incredibly okay with that not being warped. “Anyways, A wants to hang with D so C switches with A,” she finished while writing the rest of the equation.

“Why isn’t it A and C?” he asked.

“A wants the D,” she cleverly responded. Taehyung’s eyes widened in understanding. It was all coming clear. It was as though Taehyung was understanding the String Theory, Quantum Mechanics, and Calculus all in one sitting. A left B because A wanted the D. The world finally made sense. He could leave this room, run outside and solve world hunger. This was the most defining moment of his life. It had to be written down in the history books.

“Also because A and C are metals and if they switch they have to be with a nonmetal,” Wheein finished. Of course, Wheein had to crush all of Taehyung’s dreams of curing world hunger. It had to go back to what they were actually learning about.

“Then they ?”

“Yes, then they make love in a community center’s bathroom because there will never be a time they are younger and they want to lose their ity then and there.”

“Someone’s bitter,” Taehyung replied (earning a punch on the shoulder) before hearing Daehyun slam his bags onto the desk behind Wheein. It was a known fact that Daehyun had English right before this class.

It was also know that Daehyun hated English because one, it was advanced placement, and two, because his arch nemesis was in the same class. Yoon Jeonghan with his pretty hair and his pretty face. It seemed like everything he did was pretty. If he had the chance, he probably would have thrown him in a sea of Gorebyss and watch as it out all of its fluids. Wheein never understood Daehyun’s intense emotions for Pokemon or Yoon Jeonghan, but at least he had an interest in something other than food. That was all she really cared about.

But today, he seemed a little passive compared to the other days. Maybe it was because Youngjae taught him that complaining didn’t help with anything, or because there was nothing interesting to talk about. But a quiet Daehyun was never really a good Daehyun. Spinning around, Taehyung poked the boy’s cheek with his pencil eraser and a growl came out.

Wheein spun to face him as well. Nothing seemed too out of the ordinary. His head was on his binder. An annoyed look was on his face because of Taehyung’s constant hassling. Yet, Daehyun seemed better than yesterday when she heard that Jeonghan took his seat in class.

“Please kill me,” Daehyun muttered into his binder. It was that time of day when Daehyun’s inner thespian came out and entertained the group.

“What did Jeonghan do this time?” Wheein asked before shooting a warning glare at Taehyung. Why did he find poking cheeks so entertaining? There was literally nothing funny about it.

“Nothing! He has that stupid teacher wrapped around his fingers. He doesn’t even deserve the grade he got on his essay. It wasn’t even that great. How do you even grade a paper on this?!” he screeched.

Other classmates turned to him in worry, but Wheein gave an embarrassed smile. “English is going to be the end of me. How am I supposed to do well in this school if I’m always failing like this?!” he questioned. “My life is doomed,” he cried back into his arms. “I can’t even pass AP English.”

Wheein was going to open and say something, but Wonwoo sat down and gave Daehyun a double chocolate cookie which always cheered up Daehyun. Jeonghan was a part of Wonwoo’s friend group and he knew how aggravating it was to have him in class. He might have been a great friend, but nowadays it just seemed like he was cruising through his classes without a lift of a pencil. Wonwoo also just really liked his hair and was jealous that he couldn’t have luscious hair like he did.

“You’ll do fine. You can’t always please the teacher. Sometimes, you have to tolerate everything and grow resentful,” Wheein responded, trying to get the boy to feel better.

“Nice going, Miss Positive,” Wonwoo scoffed. Daehyun sighed once more before their teacher came in.

Except, it wasn’t their teacher. This handsome young man could not be their teacher. Their teacher was in his early forties, didn’t have the greatest complexion, and definitely was not the best teacher around. This man was nowhere that age. He was at most thirty-three. He came in with a suit and tie. If he smiled, some of the girls would have fainted. He had the prettiest eyes, the perfect height, and he was staring straight at the four of them. This was never a good sign.

“Why is he looking at us?” Taehyung asked.

“Does he know about your innate ability to catch everything on fire?” Wonwoo whispered back.

“Is he going to be the supervisor when we, you know, at labs?” Daehyun continued.

Wheein was speechless. Was this man taking Mr. Song’s place? If he was, there was no way she would be able to get through this life easily.

“Attractive teachers should die,” Wheein finally stated, causing the other three boys to stare blankly at her. Today was not the day for pretty sweet words, not at all. And before they could utter another word, Mr. Song, their Chemistry teacher strolled in with a happy smile on his face. It seemed as though he won the lottery and was never going to be coming back. This was also a bad sign.

“Class, this is my son, Joongki. He’s going to be the student teacher for the rest of the year, so please be kind to him. He won’t be as great as I am, but I’m sure he’ll do an excellent job of teaching.”

Student teacher?! Any thought of an attractive teacher left her soul. This could not be happening. No, the universe hated her.

“I’m going to kill him,” Wheein muttered. Student teachers plus Wheein yielded an A- and there was no way she was going to settle for an A- because some teacher had no idea what he was doing. No matter how cute the student teacher was, she was not going to become a puddle because of him. This chemical reaction was not going to happen. Mr. Song disappeared into his office while the other Song decided to take his place in front of the classroom. He thumbed through the attendance list, pronouncing every single person’s name right until Wheein’s. He stopped at her name, looked up at her, and what was going to leave his mouth was not going to be pleasant. Oh, she knew that.

“Miss Jung Wheein…” he started. She could feel the amount of students starting to swoon by the sound of his melodic voice. He probably didn’t even sing that well. He probably failed all his high school classes and decided to follow the old man to death. “I’ve heard interesting thing about you and your friends,” he continued. There was no way she was going to fall this utter bull.

“Mr. Song, I would appreciate it if you refrained from throwing shade at my peers and me. If you would like to continue this conversation, it will be outside of class. Please continue with your attendance,” Wheein rebutted calmly. The boys’ mouths dropped. Wheein was not the type to talk back to her instructors. If this girl could nonchalantly call him out on his general assumption about their lab group then there was hell to pay. No student teacher was going to give her hell for being a horrible chemistry student. Only Daehyun could do that because they did . There was no lie about that.

The man with the pretty face only smirked at her response. “I’d appreciate it if you called me Joongki. But you do have a point so I will be having the pleasure of seeing you after school today, won’t I?” he questioned with a knowing look. Wheein’s eyes widened. It was a lab day, already!? How much did he know about the four of them, and what was going to happen to their favorite supervisor, Mr. Yoo? Was he going to smite him?!

“Throwing shade, that’s a good one, Miss Jung,” he said with a grin.

Then the dreaded words came out. The words that all four of them did not like to hear after his foreshadowing.

“Now open your lab manuals to page twenty-three.”

Spinning around to face Wonwoo, her eyes widened. There was no way they had to do this lab again. The last time it happened, Daehyun spilled the unknown acid on her skin and she couldn’t even touch anything until after school. If Daehyun spilled it last time, there was no way Wonwoo wasn’t going to spill it this time. No matter how careful Wonwoo could be, he was bound to break, spill, or drop something that would cause harm to someone.

“I think the universe hates me,” Wheein whined when Joongki finally finished his instructions.

“Yeah, well, we found your Jeonghan,” Taehyung added, dragging Wheein to their lab bench. Daehyun groaned at the sound of Jeonghan’s name and then they stood there. The moment of glorious waiting was terrible.

Pipettes of different unknown liquids were being scattered about. Their group was the last one and the older man stopped in front of their lab group. It was like the eyes of God were watching. He just leaned against one of the tables while watching them prep for the lab. It was almost like a test.

Wonwoo was the first to grab his solubility rules while Taehyung started taking out the lab wells. Wheein was still stuck with Joongki. Why would he have such interest in their lab group? Why did Mr. Song feel the need to tell him about this group? Nervously, Wheein stared at the unknowns. The one with numbers were cations while the letter meant the anion.

“Mix those two together first,” she stated, praying that it was insoluble. If it was soluble, the amount of tests they would have to do would be gruesome. It meant more room for error and the probability that Wonwoo spilled something was higher. Taehyung took the two unknowns and when they reacted, it was white, purely white.

It was insoluble. This meant that there wouldn’t be so many tests to take. It meant that Wonwoo wasn’t going to be able to spill anything on her. Oh she was going to be thanking the Lord tonight.

“The only two solutions that are insoluble for this lab are Lead I Chloride and Lead I Hydroxide,” Daehyun reminded.

“Try reacting the Copper with the unknown,” Wonwoo suggested. His eyes glancing at the solubility rules. If it was soluble with Copper, it meant that it wasn’t Chloride. Chloride was soluble with the exception of Silver, Lead II, and Mercury II. Hydroxides on the other side weren’t soluble with anything except for the 1A metals.

Taehyung nodded and tried with copper. It turned clear. They managed to finish this lab in fifteen minutes. Wheein crossed her arms and looked at Joongki with a suspicious glance. For someone who was talking so much about the four of them, they managed to finish this lab a little too quickly. What was up his wicked sleeve?

It could be that he was secretly infatuated with all four of them and wanted to see how amazing they could be, but she heavily doubted that. He didn’t seem to be the type to be in a polyamorous relationship. She eyed him down. That nice looking suit wasn’t going to sway her. But before Wheein could say anything else, he was off to another group who decided that the Bunsen Burner was the best way to find out what their cation was.

Fire only meant one thing. Taehyung was heavily interested in the other lab group’s fire. It didn’t take long before the senior boy grabbed a wire, coated it with their cation and ran over to lab bench one’s fire. Flame tests were always Taehyung’s favorite part of any lab.

“Do we save him?” Daehyun asked, looking at the jumping Taehyung.

“We could,” Wonwoo continued, but he was a little more distracted by Mingyu’s grin and how he looked so confused with his pipette.

“Nah, I wanna see what the new guy does,” Wheein said with a smile.

It definitely turned blue and white like they found out in their old lab. This meant that the cation was for sure Lead I. However, Joongki wasn’t prepared for the flaming torch to come and wreck his day. The sleeve of his suit jacket caught on fire. The class stopped what they were doing to stare at the their new teacher. This was the first time that Taehyung put someone on fire. Even Mr. Yoo didn’t have that honor.

While everyone else panicked, Joongki included, the four of them started proceeding with protocol. Taehyung caught something on fire more than enough times. It became routine to fix the fire. Taehyung ushered everyone out because if he was going to make this big of a problem, he might as well only let four people know the solution.

Wheein was in charge of making sure the victim was okay. No matter how much she would have enjoyed watching her new teacher catch on fire, she jumped onto the lab bench. Her hands managed their way to turn off the gas of the Bunsen Burner, and calmly told the man to stop, drop, and roll.

Daehyun was always the one to go straight for the fire extinguisher. The only problem was that it was on the other side of the classroom. He was probably the least athletic of the four, but he knew shortcuts. Jumping on desks, sliding under tables, anything to get to that fire extinguisher. If he didn’t make it in time, there was always Wonwoo.

Wonwoo always aimed for Taehyung’s jug of water. And by that, it really was an one gallon jug of water that he brought to school everyday. It was how he became a part of the hydration nation, of course. And because his jug was always closer than the fire extinguisher, Wonwoo always ended up saving the day.

After becoming a superhero by jumping over desks to get to his jug, the real fun began. Wheein carefully sat on a lab bench and with Joongki in a panic, Wonwoo had to precisely time when he should dump the water. A flaming suit jacket was hard enough. The other hard part was getting it right on the milliseconds so it didn't grow larger. Wheein managed to keep it under control, but Joongki’s panic didn’t help. With closed eyes, Wonwoo splashed the jug straight onto Joongki.

Despite being dripping wet, Joongki still looked incredibly handsome and toned. White button downs were always a saving grace on beautiful human beings. For a chemistry teacher, he sure worked out a lot. Wonwoo sheepishly grinned at the man who seemed to slowly pull his sanity together. All four of them were a bit in awe at his figure.

The most surprising part was that the fire alarm didn’t go off. It always went off when Taehyung caught something on fire. Mr. Yoo would have told them to ignore it and continue with their lab. Joongki was not ready for what was to happen. He probably would have appreciated having the fire alarm go off. First day of class, and they were already on the field that sounded like a fun day.

Wonwoo managed to take out the fire before it spread anywhere else. But now the tables were turned, instead of a great teacher intimidating them. The four crossed their arms and smirked in response. The tides turned. This was their territory.

“Double replacement is when you exchange partners. You changed with Mr. Song and were stuck with us. Now Mr. Song has nothing, so really, it’s a single replacement,” Taehyung grinned. The new knowledge made Wheein smile in glee.

The shocked look on his face was enough for the four of them to know that he wasn’t ready for any kind of mayhem they were going to bring.

“We’ll be seeing you next week because you made it too easy this week. You should probably step up your game with us,” Daehyun stated.

Perhaps having a student teacher was going to be a fun. At least now, she had an opponent in her own endeavors. Song Joongki was going to be fun to mess with, she knew that much.

“Well, I’m glad I’ll be seeing you four everyday,” Joongki said with a grin. And before they knew it, the bell went off and the lab group didn’t have to worry about making up the lab. It was a bad omen, but they really didn’t care. They already caught their teacher on fire.