Shin’s warning was accurate. Mr. Noami was looking very unhappy today and it showed. He had prepared a pop quiz. It was the annoying kind. Mr. Noami was aware of all our weaknesses and specified each question for every student individually in topics we lacked knowledge of. It was his kind of torture. I couldn’t say it was a bad practice. By making us think about our weaknesses he is giving us a handicap by letting us know what we must work for to better ourselves. I’d even say this method was good.

  We all were looking at the board, where the third student in a row was filling out an equation Mr. Noami had previously prepared. A girl with black hair and glasses. Her hands were slow, and she hesitated. Each stroke in fear of losing points. What was her name?

  The student was struggling. Slight sweat on the forehead and the uneasy strokes on the board made that clear but this was a quiz for points for our next test.

  Helping was forbidden. If one does. We lose points.

  I let out a small breath. Looking out the window. It was raining again. The raindrops tapping on the windows slowly slid down the surface. Streak-like water remained. How typical in autumn. One of the most colorful seasons but with the ugliest weather. Rain, wind that never seemed to stop. The closer it comes to the end of this month the worse it will get. A typical November weather. The fact that this place was next to the sea didn’t help in the slightest.

  After five excruciating minutes. The student miraculously managed to clear the question and in silence left to sit back in her seat.

  “Next one will be Yuji!” Mr. Noami eyed him at the other side of the classroom.

  Everyone else glanced at him as he stood up.

  My eyes still lingered on the rain dripping down the window. Uninterested in looking at that guy.

  “A race has two thousand twenty-one entrants, all numbered from one to two thousand twenty-one at random. What is the probability that the first three runners to cross the finish line are numbered in ascending order?” Mr. Noami didn’t call him to the board but asked a question instead. He is getting it easy!

  I looked at my notebook scribbling down an answer.

  “One over six.” Yuji answered at the same time I finished writing.

  Mr. Noami pursed his lips. Here we go again.

  “And how did you come to this conclusion?” He asked Yuji, who was looking back at his teacher. A challenging look in his eyes.

  “The numbers themselves of the runners crossing the finish line are irrelevant.” Yuji answered in a monotone voice. And here I thought that sly grin he always wore was permanent decoration on his face. “Whatever they are, you can always assign a label to the first three runners across the line at random. The easiest way is to label them as A, B, and C.” He paused for a second, then continued. “Three winners. The three numbers that we call ABC in six different variations. ABC, ACB, BAC, BCA, CAB, or CBA! That is how I concluded the result Mr Noami.” Yuji said. His eyes were staring at the professor.

  This text was taken from Royal Road. Help the author by reading the original version there.

  I couldn’t tell what his face meant.

  There was silence for a long minute. Mr. Noami didn’t speak and the tension in the air was rising. Everyone around seemed to stop breathing waiting for who would react first but then someone in the back broke the silence by letting out a loud sneeze.

  I looked back at a guy whose name wasn’t in my memory.

  “Sorry!” He apologized when his eyes were met by Mr. Noami, who chose him to be his next target. Moved on with the quiz.

  Yuji and Mr. Noami developed something that resembles a cold war. I am not sure what exactly happened but around two months ago they started to be hostile towards each other. Only cold stares. When they talked the tone slightly changed in both of their voices. Though, not enough to be openly suspicious. I don’t know if anyone else noticed but it is obvious to me. The weirdest part was that there wasn’t a single argument during class. I suspect that something must have happened between them outside of class. Also, this is the only class Yuji and I never had open discussions but every other class we bickered in front of the professors many times. It’s probably because of Mr Noami's nature. He was sort of getting old at his age. Perhaps being considerate was wise.

  I was lost in useless thoughts when I heard my name called.

  “Rory Aisaka.” And here was my turn. I rose from my seat. My eyes are focusing on Mr. Noami.

  “Where can't the electron-positron pair-production take place and why?” A question was raised to me. I guess there was no point in solving the equations. I always manage to go through them with ease.

  “Pair-production is the creation of an electron-positron pair by a gamma ray photon. Energy is converted into the rest mass of the electron-positron pair and the kinetic energy they carry. A portion of the energy of the photon is turned into the rest mass of the electron-positron pair.” I answered my question with considerable ease. “This process can’t take place in a vacuum because in this case, it is impossible to satisfy the law of momentum conservation. In simpler words in a vacuum, there’s nothing to create.” Continued my explanation as all ears in the room listened. “The linear momentum of the pair is less than the momentum of the photon; this is a violation of the law of conservation of linear momentum.”

  Mr Noami nodded to my response.

  “Pair-production always takes place in the vicinity of a heavy nucleus. The recoil of the nucleus ascertains the conservation of linear momentum. If there’s nothing to conserve, nothing will be made.” He finished my explanation looking at me and the class simultaneously.

  “A very textbook answer Rory. Thank You!” He simply said. Then not even letting me take in his note he called out another name.

  I couldn’t help but look towards a certain set of eyes, looking back at me.

  It was Yuji. In class normally I struggle with these questions but today, I didn’t feel like I wanted to provoke our physics professor even more.

  After he went through questioning everyone. We opened textbooks for our next material and worked on it till the end of the class. I guess the rest of my day weirdly went okay, even though all through the day I felt this uncertain unease. I don’t know what this meant but I tried to not dwell on it by focusing on tasks for the day.