donghyuck hadn't cried reading the letter.

not that he didn't want. he just couldn't.

his eyes were aching and the lump on his throat prevented him for letting out any cry of distress.

mark was right.

donghyuck wouldn't have been able to leave if mark was there with him.

mark being at jaemin's was best for both of them.

donghyuck folded the letter preciously and caged it in a water bubble, to keep it with him forever.

donghyuck then sent renjun a flying fish, telling him about mark, the letter, his feelings and adding that he was coming back. right now.

donghyuck walked down the staris of mark's room and found himself in the living room.

he recalled the time when him and mark's friends watched the little mermaid, and the night him and mark had spent cuddling on the sofa.

these memories were dangerous.

he shouldn't think about it.

donghyuck tuned around, preventing himself from looking at the couch, and found himself facing the huge library of the room.

and that's when a book caught his attention.

it was a big blue book, with golden letters donghyuck couldn't decipher because he was standing too far from it. the merman approached it, gasping at the title of the book: 'history of mermaids since the creation of the cosmos'.

how come had he never seen it? the book was way bigger than any other book of the library.

thinking for a second, donghyuck hesitated to take it.

if the trident had to be mentioned somewhere, it would surely be in this book.

but, if it was, donghyuck wouldn't have time to find it after...

however, he could tell the other mermaids about it. and then they would find it.

the future king mermaid would accord him a favour as he helped him find the trident.

and donghyuck would ask to be able to see mark.

well, this last thought convinced donghyuck.

the merman raised his hand to grab the book and gently pulled it to take a look through its pages. however, the book was like tied to the library, and as donghyuck pulled it, he heard a mechanic noise, followed by a creaking one.

taking his hands off the book in fear, he kept his eyes glued on the library which slowly started moving, opening a tiny passage.

"mark?" he heard a voice from inside.

donghyuck entered the passage, the library closing behind him. he walked down the stairs and found himself in a huge room, well lightened and with plenty books, aquariums, tables and papers.

"oh, donghyuck! it's you. you found my lab." mark's uncle said from his desk where he was looking through papers.

"hum... yeah?" donghyuck tilted his head.

"well, you did it before mark." he pointed out. "but mark told me you were leaving?"

donghyuck tensed. "oh, yeah, i was about to leave, but i saw this big book on mermaids, and i was curious, and... it brought me here."

yongsu raised to his feet. "this is my lab. that's where i do my researches on mermaids." he explained.

donghyuck looked around. "it's beautiful. where did you find all these objects?" he asked, pointing at the various relics that were lying a bit everywhere around the place.

"they are all objects from the depths." yongsu whispered. "we found them during our scuba diving excursions. they tell a lot about the people living under the sea."

"really?"

yongsu nodded. "some of them helps us to judge the period of apparition of mermaids." he said, picking up a rusty helmet. "this was one of the first general's helmet. his name is engraved on it. are you interested in objects like those?"

donghyuck hesitated before nodding.

"you really are a good boy. my nephew would never take interest in such beautiful things." mark's uncle sighed. "anyway, all the objects i have here are rusty. that's probably because of the outside air. these things are meant to be under the water. i guess the air degrades them..." yongsu added, putting the helmet back at his place. "actually, they all turned rusty except one object. the main piece of my collection. this thing is a mystery. i'm working on it since long, but i can't really explain anything..." yongsu said, shuffling through his papers. "do you want me to show it to you?"

donghyuck nodded. he didn't really care actually.

yongsu left through a small door and came back a minute after with something donghyuck never expected to see.

the undercover mermaid widened his eyes when he saw what the human was holding.

"this donghyuck, is the most precious object i have here. it was stolen by my family decades ago. since then, we have been taking interest in mermaids and the underwater world."

donghyuck kept his eyes glued on the man standing meter before him. he was holding in his hand an enormous golden trident. this couldn't be it. donghyuck was almost sure about it. but, after all, listening carefully to what yongsu had said, it was perhaps them who had stolen it from donghyuck's people.

"you seem very interested by it." yongsu chuckled. "do you want to hold it?" he asked.

donghyuck thought quickly. if it was it, the trident would glow next to him, and once he would have touched it, he would be the mermaid that will become king of the underwater world. he had to take it.

donghyuck nodded eagerly, making yongsu chuckle again.

the man approached donghyuck with a smile, but it turned in a frown when the trident was near to donghyuck. the object was glowing. this wasn't normal.

before donghyuck could touch it, yongsu pulled it back, and plunged his hand into one of the nearby aquariums before wetting donghyuck with the water.

the merman widened his eyes, allowing yongsu to see them turning golden, and he transformed, falling on the floor because of his tail.

"i was sure you were hiding something, but i had no idea it was that!" yongsu smirked.

he threw the trident away before grabbing donghyuck on the floor and pulled him onto his shoulder as the boy was struggling. donghyuck tried to attract the trident with his powers, but he couldn't because it hadn't been activated. donghyuck hadn't been able to touch it.

yongsu brought him into the room he had picked the trident before throwing the merman in a big tank full of water. before donghyuck could do anything, he locked the tank smiling mischievously as donghyuck hit the glass wall.

"don't bother trying to use your powers. this is a 18cm thick glass cage. you won't be able to break it."

donghyuck didn't listen to him, he continued punching and hitting the hardest he could the glass.

after minutes of show, yongsu estimated it was enough.

"you mermaids are such awful monsters." he said, shuffling around the room to find something. "you killed my wife. pitiless." he groaned. "i will take my revenge. i'm sure your people will come to save you once they'll see you're missing. and this way, i'll be able to kill you whole people..." he smirked taking a small bottle out of a cupboard.

donghyuck kept hitting the glass with rage, glaring at the man.

"this is chloroform, monster. it will make you black out, and then, i'll call all my friends to share my discovery..." yongsu said, uncapping the bottle and pouring its content in the tankg donghyuck was in by a small hole that he blocked after.

donghyuck tried his best not to inhale the toxic liquid, but it had already dissolved in the water, making it impossible for donghyuck to escape what will happen.

donghyuck tried hitting the glass again, but his punches got weaker every second, and soon, his eyes shut close and his fragile body collapsed at the bottom of the tank.

ψ

it was almost 8:00pm.

mark was still at jaemin's, crying his eyes out.

jaemin had invited jeno, chenle and jisung over, to help mark smile again, but there was nothing to do. the boy had been in tears since he had come that morning, at 8:00am, and none of the boys knew the real reason. mark had told them it was about donghyuck, but he hadn't the heart to make a lie about the real story.

"mark, please smile." jeno said, his eyes turning into little crescents. "we feel bad seeing you in this state."

"b-but i c-can't!" mark yelled. "he left!"

mark really looked bad right now.

his eyes were puffy red.

tears stained his face.

his nose was running.

his hair was a mess.

his body was shaking.

he was in a really bad state, and none of his friends could understand why.

"why did he leave?" chenle asked.

"b-because he was forced to..." mark sobbed.

"yes, but you two will see each other again, don't worry." jisung tried reassuring the boy.

"no! we-" mark was cut by the doorbell ringing.

"who the hell would come at that time of the day?" jaemin asked rising to his feet. he got to the door and opened it, revealing a boy he had never seen before.

"hel-"

"can i see donghyuck, please?"