Doyun noticed the fatigue before he noticed the mistake.
It wasn't physical pain or exhaustion that could be measured. It was subtler than that, a thinning of attention at the edges of his perception. The kind that did not announce itself until something slipped through.
The morning followed a familiar rhythm. He woke, dressed, checked his watch without thinking, and left his apartment. The second hand remained frozen, as it always did. Doyun registered it and moved on.
Familiarity dulled concern.
At work, the files stacked neatly on his desk. None of them stood out. No clusters, no patterns bold enough to warrant discussion. Just small incidents, scattered and contained.
That should have been reassuring.
Instead, it felt incomplete.
Doyun spent the morning reviewing a pedestrian underpass scheduled for renovation. The site had no recorded accidents in the past year. According to the data, it was one of the safest passages in the district.
The underpass was narrow but well-lit. Security cameras lined the ceiling, and yellow tactile paving ran cleanly along the center. People passed through in steady streams, their footsteps echoing briefly before fading.
Nothing felt wrong.
That was what unsettled him.
Doyun stood near the entrance longer than necessary, watching how people entered the space. They slowed automatically, adjusted their pace, and avoided eye contact. The behavior was ordinary, almost textbook.
He waited for the familiar pull.
It did not come.
After several minutes, Doyun wrote a short note. No immediate irregularities observed. The sentence felt heavier than it should have.
He moved on.
The next location was a residential stairwell, reported for a single minor fall earlier in the week. One incident did not constitute a pattern. Still, Doyun visited out of habit rather than obligation.
The stairwell smelled faintly of detergent. A cleaning notice was posted near the handrail, dated that morning. The steps were dry and evenly spaced. A security mirror reflected the landing clearly.
Doyun ascended slowly.
Halfway up, he paused.
There it was.
Not the distortion he had grown accustomed to, but something quieter. A slight hesitation in the flow of movement. People reached the third step and adjusted their footing just a fraction too late.
Doyun frowned.
He watched a woman descend, phone in hand. She missed the edge of the step by a few centimeters, caught herself on the railing, and laughed softly before continuing.
No injury.
No report.
The space loosened again.
Doyun hesitated.
It was the hesitation that mattered.
In the past, he would have stepped back immediately, noted the shift, and recalibrated his observation. This time, he waited. He told himself it was nothing. One misstep did not form a pattern.
That was when someone behind him brushed past too quickly.
The contact was light, almost polite. Doyun moved aside instinctively, but the timing was off. The person stumbled, recovered, and steadied themselves against the wall.
Still no accident.
But the space darkened.
Only slightly.
Doyun felt it too late.
He stepped back then, heart rate rising just enough to notice. The moment passed, and the stairwell returned to its previous state. People continued moving, unaware of the near miss that had gone unrecorded.
Doyun did not write anything.
There was no category for almost.
On his way out, he glanced at the cleaning notice again. The time stamp showed the floor had been mopped less than an hour earlier. Moisture lingered invisibly, thin enough to escape notice but sufficient to alter footing.
He had missed that.
Not because the sign was unclear, but because he had assumed safety.
The realization stayed with him longer than it should have.
That evening, Doyun found himself replaying the moment repeatedly. Not the stumble itself, but the pause before it. The fraction of time when he could have moved sooner.
He had seen it.
He had recognized it.
And he had waited.
At a crosswalk near his apartment, he stopped at the curb as usual. The signal changed, and people stepped forward. Doyun followed a moment later than he normally would have.
The delay was minimal.
It felt significant.
A bicycle passed close enough for him to feel the wind against his sleeve. The rider did not slow down. They did not need to.
Doyun reached the other side safely.
Still, his pulse took longer to settle.
At home, he placed his watch beside the notes he had taken throughout the day. The pages were sparse. Fewer observations than usual. Fewer connections.
The absence bothered him more than the presence ever had.
He wrote one final line before closing the notebook.
I hesitated.
It was not an explanation. It was not an excuse.
It was a record.
Doyun lay down without turning off the light. His eyes traced the ceiling as he listened to the muted sounds of the city outside. Somewhere below, a car horn sounded and cut off abruptly.
Nothing followed.
Tonight, he understood something he had avoided until now.
Patterns did not only grow in spaces.
They grew in people.
And for the first time, Doyun wondered what would happen if he missed more than just a moment.