Potions class is not Baekhyun's favorite. It's a lot of sitting around and stirring magic soup. Today is a day that the professor wants the students to use what they've learned about various ingredients and their properties to create a potion for a specific problem.

From their ideas, including bad breath, wet socks, stuck jewelry clasps, and hair loss, Chanyeol and Baekhyun agree to tackle hair loss. Amla, Fenugreek, ginseng for vitality and vigor, curry leaves, soothing aloe, Bhringraj, a long blonde hair taken off of a classmate's robe, some honey for sweetness and to help it stick, plus some other stuff that sounds good or smells nice is all added to the cauldron.

“Kinda pretty,” Chanyeol comments. The potion darkens from a light brown to purple. “Think it's supposed to look like that?”

“I dunno.”

The doors at the back of the room open, and Jongin, a couple years behind them, slips inside. Baekhyun shyly waves with a smile; Jongin nods, ducking his head as he makes his way to the professor’s desk with a short collection of papers. They talk briefly, then Jongin leaves the way he came.

Chanyeol shifts in his seat, stepping on the corner of Baekhyun's robe. When he stands to add an ingredient to the cauldron, he stops short and bumps his hip against the table.

Unfortunately, Jongin's timing is such that he catches the upset potion. The Gryffindor recoils with a sharp gasp as boiling liquid splashes over his arms and down his hands, falling to the floor. A quick-thinking Ravenclaw offers her handkerchief with a cooling spell, wrapping Jongin’s right hand.

Baekhyun, as though struck by a stupefying spell, stands uselessly until he hears a soft sniffle. “Oh my God! Jongin, I’m sorry! Are you okay?” His hands hover uselessly, and he looks to their professor. “I’m taking him to Madam Pomfrey!”

He nods. “But come right back after taking Mr. Kim, understand?”

“Yeah.” Baekhyun gently takes Jongin’s arm, still muttering apologies while class resumes. Jongdae, half out of his seat, is told to sit down.

Madam Pomfrey lectures Baekhyun about responsibility while treating Jongin’s burns. It’s not bad, and she heals them without any scars. “And what was this potion you were making?” she asks while gathering herbs for a tea to help Jongin sleep.

Baekhyun shrugs, a humiliated blush burning over his cheeks. “I dunno. We were just kind of messing around, trying to make a potion that would make hair grow…”

“Well,” Madam Pomfrey sighs, “I’d say it’s working.” Jongin’s hair hangs to his shoulders, starting to curl. He flicks it with a finger but doesn’t say anything. “If that’s all, then it should wear off, dear, and we’ll just give you a nice haircut.” She pats his shoulder. “Will you be alright?”

Jongin nods and shrugs. His eyes and cheeks are still pink; he’s embarrassed to have cried. “I can just pull it back for Quidditch practice later—”

“You are not going to practice today, Mr. Kim. You need rest.” Her tone is final. She’s a nice woman but very strict. Both boys know protesting is futile.

“The physical wounds are healed. Rest will heal the others.” Looking at Baekhyun, she instructs, “Take Mr. Kim to the dormitory, then return to class. No detours.” His reputation precedes him; he nods and reaches for Jongin, who stands on his own and thanks the matron.

Baekhyun doesn’t know if he should take Jongin’s arm or back or nothing, so he just walks beside the younger boy. “Your hair is even longer, now. Has it always been curly?”

“Oh, yeah... It does that,” Jongin says softly.

Baekhyun likes it but doesn't say so.

An owl taps a window of the tower as they climb the steps. It carries a piece of pink paper in its beak. Baekhyun opens the window, and the owl grabs onto the ledge. Someone must have told Jongin’s professors about the accident; he’s excused for the day.

“Thanks for walking with me, Baekhyun.”

It was kind of literally Baekhyun's fault Jongin got hurt and had to be walked with in the first place. They both know it. Neither feel the need to acknowledge it. “You still showing up for practice?”

Jongin smiles. “Of course.”

The whole school knows about the incident by the time Baekhyun gets back to class. If it's not one Gryffindor blowing up his potions, it's another burning a classmate.

“Just take your seat, Mr. Byun.” The spilled potion has been cleaned, and the cauldron, books, and pens are all neatly set on the table.

“How's Jongin?” Chanyeol whispers.

“He's okay.” They flinch at the sharp slam of a textbook and quickly face the professor at the front of the room.

After classes finish, Gryffindors head for the Quidditch field for practice. Baekhyun's happy to see Jongin already dressed and talking with a couple teammates. His hair is even longer, pulled back in a thick braid.

“Aw, man, is it still growing?” Baekhyun needs to rethink his concoction. It was just supposed to make hair grow faster, not grow faster and indefinitely.

Jongin pulls the braid over his shoulder with a frown. “I tried cutting it, but it just grew back. Felt like spiders all over my scalp.” He shudders.

“I'm sorry...”

“Stop apologizing; it was an accident. It'll stop eventually, or I'll just ask the professors for help.”

Madam Hooch calls the team to the center field, telling them to get in the air, split into two groups, and prepare for a practice match. Someone suggests upperclassmen versus lower classmen, so Baekhyun and Chanyeol face off against Jongin and other fourth and third-years.

For a while, things go well. Bludgers are batted and Quaffles are thrown and intercepted. Baekhyun keeps an eye out for the Snitch and spots it a few times, but it's flighty and fast. He's close when he spots Jongin in his peripheral view, watching his teammates and signaling he's open for a pass; he doesn't see the rogue Bludger dodge a bat and hurtle straight for him.

Just as Jongin's knocked off his broom, Baekhyun flies into a tower stand. He untangles himself in time to see Madam Hooch pointing off the field and Jongin nodding, holding his ribs.

Upperclassmen win the practice match. Jongin doesn't return, but he's not in the infirmary or dorm, either.

“Maybe he went to one of the professors about the hair thing,” Chanyeol suggests. He tosses his robes over the chest at the end of his bed and pulls a T-shirt on. “If it doesn't stop growing, he could be in a lot of trouble. Where would he keep it all? How would he move around?”

“You're very reassuring.” Baekhyun closes his trunk and drops onto his bed. He's tired, although it's still early. Traumatizing a friend and humiliating himself is exhausting.

Jongdae bursts into the dorm, scowling and eyebrows drawn in a deep vee over his nose. He growls and leaps for Baekhyun, pinning him to his bed and looking angrier than he’s ever been. Tan, the eldest Kim brother's cat, shrieks and bolts down the stairs.

“What did you do to my brother?”

Shocked by his friend, Baekhyun stares dumbly, looking at Chanyeol for help, but he looks just as stunned and hovers nearby, unsure what to do.

“He’s locked himself in the boys’ bathroom and charmed the doors and windows so they won’t let anyone in! You’re the last person he talked to, so talk fast, or you’ll never talk again.” He taps his wand under Baekhyun’s chin.

“I-I-I didn’t do anything? You saw in Potions, I spilled a cauldron on him, he got burned, and Madam Pomfrey healed him!”

“Dae…” Chanyeol carefully takes Jongdae’s shoulders like he’s dealing with an enraged cat, pulling him off Baekhyun. “Did you talk to him?”

“All he’s saying is it must’ve been something in Baekhyun’s potion,” Jongdae seethes. He twists his wand in his hands. Normally, he's a relaxed and cool-tempered person, but he becomes an overprotective beast where his little brother's concerned.

“Let’s get a professor to open the door,” Chanyeol suggests. “If he’s hurt, he needs to go back to Madam Pomfrey.” Baekhyun nods frantically, smiling in what he hopes is a reassuring manner.

Jongdae scowls but nods, tucking his wand into his pocket.

As they file down the stairs—Chanyeol first, then Baekhyun, and finally Jongdae, as though to prevent any attempts at escape—Baekhyun apologizes. “I really am sorry, if this is my fault.”

“Of course it’s your fault.”

Baekhyun wilts. He doesn’t like his friend being upset; being upset at him makes him feel even worse. “Let me try talking to him. It could be a misunderstanding. Maybe he thought I did something on purpose. I’ll apologize again. Let’s not go to a professor just yet, okay?” Their house has been losing points, lately; they can't afford many more or fall behind Slytherin.

“...Fine.” Jongdae relents. “You’ve got one chance, then I'm getting McGonagall.”

Chanyeol tries the handle of the bathroom door, but it's shut tight. Baekhyun tries the alohamora spell, and it seems to work, but the lock returns to its place right away. Holding his wand in his fist, he knocks three times and waits.

“Jongin? It’s Baekhyun. Your brother said you won't open the door. Are you okay?”

They hear a sniffly sigh. “Yeah. I’m fine.” His voice is pitched funny, a poor attempt to disguise his tears.

“Jongin, will you let me in? I want to apologize. I didn’t mean to hurt you with my stupid potion. It was an accident!”

“I know. My arm’s okay.”

“Was it practice? I saw you take a hit. It really hurts, man! I've been there.” Lots of times. He's pretty sure some of the bruises are permanent.

“...No.”

“He sounds weird,” Chanyeol mutters. Jongdae glares at Baekhyun. He's on borrowed time.

“So what’s wrong? Let me in, or come out and talk to me? Jongdae and Chanyeol are here, too. They’re worried.” He looks to them for some kind of backup.

Jongdae sighs. “Jongin, please come out. You haven’t eaten anything since breakfast.”

“I had snacks…”

“That’s not a meal!” Jongdae scolds. “Please—just come out, Jongin. Whatever it is, it can’t be that bad. I can all but guarantee we’ve seen and/or done worse.”

“...Promise you won’t laugh.” The locks flip open, and the door pulls inward. Jongin stands behind it, looking at the floor. His hair is loose, still very long, sticking to the tearstains on his cheeks.

“This isn’t bad!” Jongdae says brightly. “We can just cut your hair.” He holds out a hand. “Let’s go get something to eat.”

“It’s not just my hair…” Jongin shyly steps out from behind the door, and the older boys all turn pink.

“Baekhyun…” Jongdae rounds on the boy, bony fist striking Baekhyun's nose. “What did you do? It's bad enough you have a crush on my baby brother, but you can't just like him as a boy?”

The transfiguration potion either has a side-effect or a different purpose all together. Jongin’s figure has turned curvy, with an even narrower waist and wider hips, and his shirt strains a bit at the buttons, not fitted to accommodate s.

Baekhyun pulls his sleeve over his hand and holds it to his nose. Nothing he could say would make anything better, but he likes Jongin no matter what. He very much regrets asking Jongdae the supposedly hypothetical What if I had a crush on your brother?

“You’re still cute, Jongin,” Chanyeol comments unhelpfully. Jongdae glares at him, and he flinches. “What?”

Taking Jongin's elbow, Jongdae mutters, “...Let’s go see Madam Pomfrey.”

The matron is not happy to see them again. After stopping Baekhyun's bleeding, she briefly examines Jongin, mending the bruise from Quidditch practice, and offers a hopeful prognosis. “Well, dears, the good news is transfiguration potions and spells are not permanent. It’ll probably wear off in a day or two.”

“That long?”

“The bad news is I have to report you, Mr. Byun, to the headmaster.”

“But it was an accident! And it was during class, the class it was meant to be in! Jongin was only there to hand in an assignment. It wasn’t anything against the rules.” Glancing frantically sideways, Baekhyun quickly adds, “Not that I'm trying to blame anyone else! It was just...” his shoulders fall, “an accident.”

“He does have a point, Madam Pomfrey,” Jongin comments softly, staring at his chest with a pout. He feels weird and doesn’t know where to put his arms to hide himself. Chanyeol offers his robe; it hangs more comfortably over his unfamiliar figure.

The witch rolls her eyes, sighs, and shakes her head. “Just this once, I won’t say a word. But if you put a single toe out of line again, Mr. Byun, the headmaster will hear about it.” She shoos them with her hand. “Now off with you.”

In the hall, Jongdae, Chanyeol, and Baekhyun arrange themselves to hide Jongin as much as possible. “I'm going to see my brother before going to bed,” Jongin says.

“I'll come with you.” Jongdae walks to his other side. He's still mad enough that he won't look at Baekhyun. He and Chanyeol quietly say good night and head back to Gryffindor Tower.

Dropping onto an armchair in the common room, Chanyeol rubs his arms and scoots closer to the fireplace. “How's your nose?”

Baekhyun slouches on a sofa, opposite another student who's fallen asleep with a book on their lap. A toad croaks softly on its open pages.

“I'll live.” Groaning, Baekhyun slips down the cushion until he's only hanging on by an arm over the armrest. “I just feel so bad! I didn't— It was a stupid potion. I don't know what went wrong, but I don't know what would've been right, either! We were just making it up.

“Now Jongin's a girl. Jongdae hates my guts and thinks I changed Jongin on purpose. I'm so close to detention I can feel the mind-numbing boredom. And if we lose the house cup this year, it'll probably because of my continued assaults on the object of my one-sided crush.”

As head boy of Ravenclaw, Joonmyun arranges for Jongin to use the prefects’ bathroom, to avoid the boys versus girls dilemma. He tells the others Jongin is sick and doesn’t want anyone to see or catch what he's got, and they’re sympathetic—if not a bit grossed out by the idea of random pustules bursting from all over the body.

The safest place from prying eyes is the infirmary. After a day of laying in bed and having his homework brought to him, Jongin returns to Gryffindor Tower. He's still not completely back to normal.

“I really am sorry, Jongin.”

“I know. I don’t blame you.”

“I wonder what I got wrong. It was just supposed to make hair grow, not...anything else.” He gestures to Jongin’s body. “Not that you don’t still look good or anything. Long hair actually kind of suits you? It’s really pretty and soft.”

“I had to cut it again because of how tangled it got during practice.” Jongin pulls it all over his shoulder. “It grew back—obviously—but it didn't grow as fast? I think it's wearing off.”

“That’d actually be pretty neat, wouldn’t it? Perfect hair, no matter what. I bet I could market that...”

“Side effect being a change?”

“Well...it has a couple wrinkles to iron out.” Baekhyun watches Jongin comb his fingers through his hair until he realizes he’s staring and looks at the painting on the wall, instead. The subject crosses her eyes and sticks her tongue out. He mimics the expression and hears a soft snicker beside him.

“I am sorry, Jongin. I really messed up.”

“It was an accident.” Deja vu. They've had this conversation before.

“I think you're the only one who really believes that. Every time your brother looks at me, I swear he's reciting hexes in his head.”

Jongin bumps his knee against Baekhyun's. “Don't worry about that. He won't actually do anything. In a couple days, Madam Pomfrey says the effects will wear off completely, right? No big deal.”

“I still feel bad, and I’m pretty sure Jongdae hates me.” There was a pile of opened boxes of chocolate frogs without the chocolate frogs on his bed. They were melting under his blankets as he’d slept, and he woke up very sticky after a nightmare of tortured frogs’ croaking.

“Don’t worry about Jongdae. He’s just being overprotective.” Jongin sighs, acknowledging the burden.

“I’d just like to repay you, somehow. As another apology. No matter what, I—I would never intentionally hurt you in anyway.”

“I know.” Jongin pushes his hair behind his ear, then pulls it all over his shoulder again. “And if you wanted, we could go to Madam Puddifoot's sometime? Or even The Three Broomsticks. A bit less pink...”

“Really? You’d go with me? I’ve been wanting to ask, but—” Jongdae. And anxiety. Self-doubt. Baekhyun’s great with putting himself out there for the sake of making friends; he’s a goofy sort of person, but there’s always a lingering fear of judgment and rejection, especially when it comes to deeper connections.

“I think it’d be fun to go with you.” Jongin drops his knee outwards, bumping Baekhyun’s. Baekhyun bumps his knee in return, noticing the shape of Jongin’s legs aren’t as curvy and soft as they had been.

His potion was a failure—receiving a solid dreadful mark—he physically and emotionally scarred his crush, plus one of his best friends is probably going to continue inconveniencing his daily life, but sweet, kind, handsome, and forgiving Jongin asked him out, anyway.

Baekhyun’s feeling pretty good about himself again.

---

a/n: Written for Ethereal Boys round 3 (prompt no.R266 Potions class ends up in disaster when Baekhyun accidentally splashes the brewed liquid onto Jongin and slowly he transforms into.... a girl?? In which the effect will last for 48 hours.)

I spent too much time trying to figure out the timeframe for this setting. It's not even that important, but it distracted me from the actual story enough that I honestly rushed it.