"Electrochemistry. No… Not this...Not this too. Human Reproduction. Hmm, interesting. Ahhh... No. Damn it. Where is it?" Surrounded by the tall shelves in the library, I stood alone in the darkness. Sweat ran down my face as I ran my fingers through the books, illuminated dimly by the phone's flashlight. 

"Why does this happen to me every time, and that too just before such a crucial day?"

"Hey! What are you doing there?" A man's voice called me out. I pointed my flashlight towards the direction of the voice. The man looked probably in his mid-twenties, wearing a shirt that was buttoned unevenly and messy hair.

"Don't worry. It won't take me long. I will be gone once I find it." I replied.

He stepped towards me, "What do you need in the middle of the night from the library? Listen, kid. This can be considered as a break-in. I would ignore this one time because I am just too tired right now. Just go home now and come tomorrow in the morning for whatever you need." He said in a calm tone as he pretended to rub his eyes.

"No. This is urgent. I can't return home without it. So go back to what you were doing." I turned towards the shelves and continued my search.

"Tch.." He grabbed my arm and pulled me towards him. "Do you want me to call the police? You stupid brat. Can't you understand the situation you are in? Just go home!" He suddenly snapped and shouted at the top of his voice.

I grabbed his hand with my other hand and squeezed it tightly. "Ahh..ngh…" he cried out in pain and his hold on my arm loosened.

"If you call the police, you will be the one getting arrested." I r

"What are you talking abou...Ah..ngh!" I strengthened my grip and twisted his arm. His face went taut and his knees trembled.

"I heard that you recently became the new librarian after the previous one got crushed by the shelves."

His eyes widened in surprise as I mentioned the librarian. "It...It was just an accident." He stammered.

"It was no accident. You killed him!" I pressured him. He was starting to break.

His face turned pale. "Why would I kill him? He was my mentor. He took me in and gave me a job here in this library. Besides, the police already declared it an accident. How could I have done it? Even the cameras didn't catch anything." he muttered.

"I wonder who could have successfully performed such a task? Maybe someone who knows where all the cameras are."

"What Nonsense!? He once again raised his voice. "That's bullshit! You can't prove it. And why would I even do it? Just for a position as a librarian?" he asked.

"No. Eventually, he would have passed on the library to you. He cared for you like his own son. You wanted something from him that you could never have. You wanted his wife from the beginning, didn't you?"

"Wha..." I twisted his hand once again. "Ah..ngh..ahh" his legs gave in and he fell on his knees. He grabbed my arm and made a futile attempt to free himself making my phone fall off my hand, with the face down on the floor. The phone's flashlight illuminated my face and my crimson-purple eyes from below.

Thud. A sound of furniture falling came from the staff room.

"Tell me. What were you doing this late at night in the library? Or should I ask who you were doing? She is inside the staff room, isn't she?" Just one more push and he will break. A smile flashed across my face.

"Ho..how did you find out?" He asked.

"How? There are two reasons.

First - I know how people betray even their loved ones, once they want something even more than their affection towards them. I always keep an out for people like that.

Second - I can see the Demons hidden inside people."

I let go of his hand. He fell on the floor on his back and grabbed his hand, agonizing in pain. I looked down into his eyes.

"AHH..NGHH" He grabbed his head with both his hands. "What are you doing? Stop it!" The man averted his eyes, trying to avoid looking straight into mine. "What are you doing to my head? It hurts. It feels like it will blow up. Please stop!" He begged, "You want money? You can have all of it. Just stop this. I can't stand it. Why are you doing this? Just leave me alone!"

"No. I don't need money."

"What do you want? WHAT ARE YOU!?" He cried out.

"I am the Demon King and all I need is Advanced Physics Volume 3. Because tomorrow, I have got a test to pass."