THE EQUATION

The first thing Lina Morgan noticed was the silence.

Not the peaceful kind-the unnatural kind.

The lecture hall was rarely quiet. There was always someone laughing too loudly, chairs scraping against the floor, someone else complaining about attendance or unfinished assignments. But today, the air felt suspended, as if the room itself was holding its breath.

Lina slipped into her usual seat near the middle row, tugging her bag closer to her feet. The projector screen glowed blank at the front of the room, untouched. The board was clean. No equations. No name written yet.

A substitute, she'd heard.

Someone had whispered it behind her as she opened her notebook.

"The math professor's on vacation. We're getting a temporary lecturer."

Lina barely reacted. Professors came and went. Temporary people were easy to ignore. This was her final year-she'd learned how not to attach herself to things that didn't stay.