Theorem of the Untold

Teaser:
Chapter X: Logic and Lies

I stood at the board, marker in hand, my heart pounding as the eyes of the classroom pressed in on me. I could feel the professor's impatience growing as the seconds ticked by, the hated equation looming large on the board in front of me. Numbers danced in her head, but the right answer seemed just out of reach.

For a moment, I hesitated, glancing over my shoulder at the rows of desks, then back at the problem. I'd always been careful, always kept a boundary between myself and it, only letting the voice linger at home, never here, never in the open.

"Seventy-four~"
"I-I... the answer is... well, seven-uhm..."
"Seventy-four~" the voice whispered again, low and cold against my ear.
"SEVENTY-FOUR!" I blurted, the rush of relief spilling out too quickly.
My maths professor blinked, startled. "That's... correct, Amira!" He said, though his tone carried an edge of disbelief. But I wasn't paying attention to him anymore. My eyes had already darted toward him.
He finally looked up from his notebook, brows furrowed. There was a brief, curious pause as if he'd just noticed I existed. My heart raced, but I kept my expression neutral.
"Wow, Amira," the professor went on, scrutinizing the board now. "That's really impressive. But... your working out is completely wrong."
I swallowed. "Uh... I guess I worked most of it out in my head..."
"No credit for me?~" the voice whispered again, smug and close.
"Shhh," I muttered.
"What?" My teacher frowned.
"No, no-uh, not you!"
"Alright, Amira, take your seat."
I nodded, walking back to my desk. I could feel his eyes lingering on the board, puzzled, maybe even suspicious. I resisted the urge to look back.

I did it. I finally caught his attention. But now I wondered-could I even call him my academic rival anymore? Or was I dealing with something far more dangerous than competition?