Author's note: I forgot to say that full italics sentence means thoughts. Whose thoughts? I hope the context makes it clear.

“Donghyuk!”, Yunhyeong shouted as he dashes toward Donghyuk and pats him on the back. “Are you going to beast mastery class now?”, he continued.

Donghyuk hums in agreement. “How’s your potion class?”, he asked.

“Not much. Just the usual boring stuff.”, Yunhyeong replied, circling his arm around Donghyuk’s shoulder.

“That’s because you’re naturally good at mixing ingredients.”

Yunhyeong smirks at the compliment. “You know, I can teach you. A private lesson, just you and me.”, he said while drawing circles on Donghyuk’s chest.

“I don’t take potion class.”, Donghyuk responded, trying to sound gentle but ended up sounding nonchalant. Yunhyeong can only pout at the response.

Seeing Yunhyeong’s disappointment, Donghyuk quickly shifts the topic. “What do you think of our teacher?”

“Oh, that Junhoe guy? He’s new, right? He’s not bad, I guess. A bit… unusual, compared to other teachers.”

“Unusual how?”

“I don’t know. I just have a weird feeling. Like, he doesn’t seem like a nice guy; I don’t think he cares about us at all.”, Yunhyeong explained. They reach their classroom before Donghyuk can respond, and Junhoe is already there, sitting behind the teacher desk, reading a book that may or may not be alive; so Donghyuk will need to hold his respond for other time.

As soon as they enter, they were alerted to the presence of Chanwoo at the back of the room. Chanwoo has been attending Junhoe’s class. Well, not all of them; he’s only there when his assistance is needed. But, when he’s there, it indicates that the students are going to do something rather fun. What are we going to do today?

When the clock reaches 12 PM, Junhoe stands up from his seat and starts talking to the class. “Today we’re going to talk about… Mermaids.”, Junhoe said.

“A very popular creature, many people think that they use their songs to lure their victims. Unfortunately, that is only true for a few northern species. Most of them use their songs for breeding purpose: to find a mate.”, Junhoe continued.

He then takes a few crystals from his bag and arranges them in front of the class. After they’re arranged properly, he makes a few magical hand signs while resuming his explanation. “It’s summer right now in the southern area, about 25°C, warm breeze, gleaming moonlight; perfect for holiday… and Mermaids’ breeding season.”

After a while, a portal opens, followed by a few “Whoa…” from the class.

“We’re going there.”, Junhoe explained. “It’s not a trip. We’re observing; bring your notes.”

Hearing that they’re going on a not-trip trip, the students get reasonably excited. They start chattering among themselves. “Whoa! This teacher rocks! Isn’t this exciting?”, Yunhyeong enthusiastically said as he leans toward Donghyuk.

Donghyuk sighs. “I have a bad feeling about this. I don’t think a rowdy class like this can handle something like that.”

While the students are chatting, Junhoe calls Chanwoo. “I want you to get inside the portal and check for anything dangerous on the other side.”, he ordered, pointing at the portal with his thumb.

“Eh…! Why me!?”, Chanwoo tried to protest, but Junhoe quickly shuts him up. “You said you'd help me. It’s part of the deal.”

“Yeah, but I didn’t…!”

“Just do it already! You’re wasting my class time.”, he said, shoving Chanwoo into the portal.

Chanwoo smoothly plunges through the portal toward the ground. “Ow!”, he said, rubbing his arm, but any pain soon disappear as he gets to see the place across the portal. It’s a river, beautifully located inside a forest. The river flows toward what seems like a lagoon from a distance, although he’s sure that that is the ocean. However, the most striking feature is the river’s glow. Yes, the river is glowing; emitting some light-blueish radiance. Usually, this indicates some kind of magical creature inside the river.

After a minute or so, Chanwoo returns. “It’s clear.”, he said.

“Great! Ok, everyone, enter the portal one by one. Don’t separate from the group.”

The students start entering the portal. Once everyone has arrived at the other side, Junhoe and Chanwoo follow them. As soon as they landed, they can start hearing the songs; a stream of sound that can be best described as melodic wailing.

Junhoe swiftly strides to the front of the group, leading them to stroll by the riverside, while Chanwoo walks alongside the group. “Now, although Southern Mermaids do not use their songs to find meals, a human can still be charmed by their songs. Charmed human will interrupt their mating, often to a dire consequence. So, do not enter the water at any time. Your death is not my responsibility.”, Junhoe explained.

Donghyuk and Yunhyeong are walking slowly right at the very end; not really listening to Junhoe, opting instead to leisurely enjoy their journey.

“It’s such a beautiful place, isn’t it?”, Donghyuk asked. However, he gets no response. Donghyuk turns to the right to check where Yunhyeong is supposed to be. “Yunhyeong?”

Realizing that Yunhyeong is no longer there, he starts looking around. Checking if Yunhyeong dashed to the front, checking if he got separated. But then, he looks at the water, and a sudden realization hits him. “Oh, sh…!!!”

He quickly runs to the front and tugs Junhoe’s shirt. “I think Yunhyeong went into the water.”, he said, pointing at the river.

Looking at Donghyuk’s panicking face, Junhoe takes a long groan while massaging his forehead with his fingers; obviously frustrated. “I thought I said not to enter the water just a few seconds ago.”

“Well, we were at the back, and…”

Junhoe ignored Donghyuk’s remark. Instead, he walks to the area that Donghyuk pointed, and crouch while staring at the water.

“What are we going to do?”, Chanwoo asked as he approaches Junhoe.

“Can’t we just let him die?”, Junhoe asked nonchalantly, much to Donghyuk’s horror. Chanwoo cannot even tell if he’s joking or not.

“You know, natural selection?”, Junhoe continued while staring at Chanwoo. Chanwoo just stares back at him with a disapproving gaze, not saying anything.

“No?”, Junhoe asked again.

“No.”, Chanwoo finally said.

Junhoe sighs. “Fine. Lead them back to the classroom; I will handle this.”, Junhoe ordered while gesturing at the students.

“But… Can you handle this alone? I mean, you just said how dangerous it is to enter the water.”

“Why? Are you worried about me?”, Junhoe asked sarcastically. But, to his surprise, Chanwoo gives a serious reply, “Of course I do! Am I supposed not to?”.

Junhoe stares at Chanwoo’s intense gaze. He then closes his eyes and takes a deep breath. “You know what, I changed my mind. Let them stay. It’ll be good to teach them how to save someone from Mermaid’s song.”, he said while standing up and continue walking.

“If someone got charmed by mermaids, the first thing you need to remember: don’t be stupid. Jumping into the water straight away isn’t going to help. First, you need to locate the lost guy.”, he explained. While explaining, he will occasionally stop and look at the river; throwing a detection spell or two.

But then, he suddenly stops.

“What? What’s wrong?”, Chanwoo asked.

“That.”, Junhoe pointed at the river. “That’s not a mermaid.”

“Is that him?”, Donghyuk asked.

“No… That’s…”, Junhoe said while crouching to inspect the body of water. Before saying anything else, his eyes become wide with realization, and he suddenly jumps into the water.

“Wait, Junhoe!”, Chanwoo shouted, to no avail. “Oh, sh…!”

“What are we going to do now?”, Donghyuk asked, panicking even more.

“Go back to the classroom and wait there.”, Chanwoo instructed the students, including Donghyuk.

Donghyuk tries to protest, “But…”.

“There is nothing you can do here. Just go back. We’ll bring Yunhyeong back.”

Donghyuk finally acquiesced. He and the other students walk back to the portal.

As soon as they leave, Chanwoo looks at the water. “What am I supposed to do now?”

But suddenly, he notices that the water level rises and the waves become stronger. Something is happening inside the water. He paces back and forth for a while, not knowing what to do. But, the waves keep getting more violent.

“Oh, whatever! If I die, I die!”, he yelled as he jumps into the water. The moment he gets inside, he can see something; something that is obviously not a mermaid. It has a huge serpentine body, but it’s not a dragon… It’s a Leviathan! He has heard of it before, but never actually see one. It’s definitely bigger than anything he has even seen.

And it looks… angry? It’s raging all over the place, destroying everything that gets in the way of its berserk.

Oh, no! I’m absolutely going to die!

But that’s not the worst part. Because… there are two; yes, two, Leviathans! And yet, for some reason, they seem to be… fighting? They are both similar in size, so it’s not clear who will win. In fact, they look exactly the same! Chanwoo doesn’t know if his eyes are deceiving him, or if Leviathans are supposed to look like they’re cloned.

But, it’s not the main concern; he needs to find Yunhyeong and Junhoe, and quickly returns to the surface. Alas, one of the Leviathan notices Chanwoo. Their eyes meet for a while, and the Leviathan suddenly strikes Chanwoo with its tail, throwing Chanwoo out of the water and high in the air.

Chanwoo shouts mid-air. “Oh no, oh no, oh no!!!”

“What should I do now!?”, he screams as he freefalls from the sky.

Then he remembers something.

“Cast a spell, cast a spell!”

He immediately starts forming some magical hand signs and shouting an incantation. He can see the ground getting closer and closer.

And finally, he lands. The spell cushioned his landing; it’s still painful, but at least he’s not injured.

He stays on the ground for a while, out of breath. Once he regained his strength, he stands up and stares at the water. I’m not going in again!!!

Fortunately, he doesn’t need to go in. After a while, the water gets calmer. Soon afterward, Junhoe comes out, with Yunhyeong on his shoulder.

“Junhoe!”, Chanwoo shouted, moving straight away to help Junhoe gets out from the water.

“Did you see what happened? There is a…!”, Chanwoo muttered energetically.

“Leviathan, I know.”

“And not only that…!”

Junhoe holds out his hand to stop Chanwoo. “Wait.”, he said, still trying to catch his breath.

“Oh, sorry…”

Junhoe then sits on a nearby stone. After he takes a few deep breaths, he says, “Ok, go on.”

“How did you save him?”, Chanwoo asked, pointing at Yunhyeong.

“Trade secret.”, Junhoe said, refusing to give out any detail.

“Ow, c’mon!”

“Seriously, it’s a long story.”

“Will he be alright?”

“Yeah, he’ll wake up after a while.”

“Oh, right! Did you see the two Leviathans?”

“Two?”, Junhoe asked, staring confusedly at Chanwoo.

“Yeah! There are two Leviathans! There is no way you can miss the other one.”

“Nope, I only saw one.”

“But… I’m sure I saw two!”, Chanwoo insisted.

“It’s the Mermaid’s songs. They can make your head all weird.”, Junhoe explained.

Chanwoo wants to argue back, but he realizes it doesn’t really matter. They’re all safe, and that’s the important bit. So Chanwoo simply concedes. “Alright then, I trust you.”, he said, staring at Junhoe, who was staring at him, but immediately shifts his gaze when he realizes Chanwoo is staring back.

“Anyway, I don’t know that Leviathan is that huge!”

Junhoe smirks at Chanwoo’s remark. “That’s just a baby.”, he said while standing up.

“Eh!? That’s just a baby?”

“Adult Leviathan is way bigger than that. That one is probably only one-year-old, maybe slightly older.”, Junhoe explained and started walking toward the portal.

“No way!”, Chanwoo said, lifting Yunhyeong’s still unconscious body and starts following Junhoe toward the portal. “But why is it in the river? I thought Leviathans live in the sea?”

“It’s probably lost. As I said, it’s still young. That’s also why it’s rampaging. It’s not angry; it’s scared.”

Donghyuk is pacing back and forth; eyes keep staring at the portal, waiting for their teachers to return, hopefully with Yunhyeong.

“Just calm down.”, one of the students tried to comfort him.

Of course they can say something like that; they barely know Yunhyeong. Donghyuk isn’t ready to lose the precious being known as Yunhyeong yet.

Finally, he sees someone going through the portal. The teachers are back, and Yunhyeong is with them! It seems that Yunhyeong regained his consciousness on their way to the portal, as Yunhyeong is now walking with Chanwoo’s help.

“Yunhyeong!”, Donghyuk shouted, immediately running to take Yunhyeong from Chanwoo. “You stupid, stupid Yunhyeong! That’s why you must listen to the teacher!”, Donghyuk complained, before hugging Yunhyeong as tight as he can. “Don’t make me feel like this ever again…”, Donghyuk whispered quietly at Yunhyeong’s ear.

Yunhyeong can only laugh at Donghyuk’s sweet side. “Don’t laugh! There’s nothing funny!”, Donghyuk whined as he hits Yunhyeong’s back twice, but then continue hugging him again.

Chanwoo smirks at the sudden display of lovey-dovey in front of him, while Junhoe simply rolls his eyes.

“I’m surprised you guys are still here.”, Junhoe said sardonically. “What are you waiting for? Our time is up. Class dismissed.”, he declared.

As the class starts disbanding, Chanwoo stands next to Junhoe. “Good job today.”, he said.

“Good job? You call that a good job?”, Junhoe asked as he closes the portal.

“Well, if it’s not because of you, I will never experience something like that.”, Chanwoo said, smiling earnestly at Junhoe.

Junhoe turns around to look at Chanwoo, but immediately turns back again when he sees Chanwoo’s smile. It’s not that he doesn’t like Chanwoo’s smile, it just feels… odd. His heart beats so fast like it’s protesting.

“Let me make you dinner for today.”, Chanwoo offered. Junhoe doesn’t reply, instead taking his bag and walks away with a small grunt. That means yes.