If A is A Then, N is N

That night, Jimin slept peacefully, at least. He set aside his worries and thoughts before he was engulfed in a deep slumber. But, he was awaken when he heard their shared room's door creaked open, silently. He opened his right eye, followed by the left one, squinting his eyes to look at Taehyung who seemed to be quiet in the steps he's making.

"What time is it?" he asked himself. He looked at his alarm clock beside his bunk bed, 01:57 a.m. The time read.

"Will probably drink water." he mumbled to himself and drifted off to sleep.

"Jimin, get up," Taehyung shook Jimin's shoulder trying to wake him up. He groaned and said, "Wake up, Namjoon-hyung have something to tell us. It's about Jungkook." Jimin jolted and sat up immediately in his bed.

Taehyung grinned. "Let's go." he said. "It's just 02:30 in the morning, what about Kookie?" he asked his friend. "I don't know." Taehyung shrugged his shoulders.

He went to the kitchen with Taehyung. "What's with the noise?" Taehyung asked.

"Blame Hobi." Yoongi said. "What?" Hoseok asked him.

"What." Yoongi replied.

"Guys, settle down, we need to talk about something," Namjoon said. He cleared his throat and spat the words, "I received a message from Jungkook just earlier."

Everyone gasped. "Wait, what? What did he said?" Seokjin asked, confused. "I miss Kookie! When will he be back?" Jimin asked, excited.

"Can you read the message for us?" Taehyung asked. "Jungkook will be back soon!" Hoseok happily shouted making everyone cover their ears.

"Can y'all shut up? You're too loud, I think my eardrums are damaged. Let Namjoon read the message." Yoongi said in an irritated tone.

"So, like what I was talking about, Jungkook sent me a message, exactly at 02:02 a.m.," Namjoon said. "It wasn't a normal message, I thought he just pressed the buttons randomly but, what's bothering me was the question, "Looking for your friend?" and there was I think some sort of code with the sentence "If A is A then, N is N." he added.

"May I see? May I see?" Jimin asked. "Uhm... Ok, here you go." Namjoon hesitantly gave his phone to Jimin.

"I can't understand anything." Jimin said making almost everyone facepalm. "Let me see it." Yoongi stretched out his palm for the device.

"It doesn't make sense." he said. "I think its a code." Namjoon said his thought.

"Then what kind of code? There's a lot of it as I can remember." Seokjin said.

"I don't exactly know what is what, but the last sentence can help." Namjoon said.

"What does the last sentence said?" Taehyung asked. "It says, "If A is A then, N is N." Namjoon answered.

"Can you pass a sticky note from the fridge, Hobi?" Namjoon asked Hoseok.

"Here," and he handed him the paper. Namjoon wrote the letters from Jungkook's message. ZSZPSMHTWQ.

"This is what I think the code is, from the message." Namjoon showed them the paper. "I know some codes." Yoongi said.

"Can you tell us some? It can help."

"Ever heard of Morse Code? But that's definitely not a Morse Code." Yoongi said. "Let's give a try on ROT13, it is the most similar one presented in here that I knew." he added.

"Can you show us how?" Taehyung asked.

Yoongi wrote down the ROT13 on the paper:

A=Z

B=Y

C=X

D=W

E=V

F=U

G=T

H=S

I=R

J=Q

K=P

L=O

M=N

The answer he got was, AHAKHNSGDJ.

"The actual fuck! It still doesn't make sense." Yoongi said, frustrated. "Yoongi, calm down, we still can try others, we'll help you." Seokjin held his shoulder.

"If A is A then, N is N..." Taehyung said, thinking on what does that means. "Yoongi-hyung, can I borrow the paper?"

Yoongi gave him the paper and Taehyung started to scribble. He wrote A=A and N=N vertically with a big space in between those two.

"I think I'm getting what you meant, Tae." Namjoon said, amazed on how genius Taehyung was. He smiled proudly at his friend, dimples showing off. "Right." Taehyung smirked.

"What are you guys doing?" Jimin asked, puzzled. His brows knitted. "I think they're communicating." Hoseok answered him. The two idiots conversing. "Why won't they tell us? I can't understand a single thing."

"Jimin, Hobi, can you two shut your mouths? Let Joon and Tae concentrate on what they are doing." Seokjin hushed the two. They sheepishly grinned while showing off a peace sign.

They all looked at Namjoon and Taehyung as the two high-fived. "We got the answer." Taehyung said. "And its all thanks to Taehyung." Namjoon said.

"What is it?" Yoongi asked. Taehyung showed them their scribbles.

A=A

B=Z

C=Y

D=X

E=W

F=V

G=U

H=T

I=S

J=R

K=Q

L=P

M=O

N=N

ZSZPSMHTWQ= BIBLIOTHEK

"Now that does makes sense." Yoongi grinned.

"Isn't it the city's library?" Seokjin asked. "The one outside the uni?" Jimin asked too.

"Yes, and we're going there later, after our classes." Namjoon announced. "Alright everyone, get ready for your classes, its already 03:36, we spent almost an hour working on this code," and with that he sighed and left, getting ready for the day.