Haunting

Chapter Three: Subsitute

When Aizawa asked him to fill in for the afternoon, he hadn't expected this would be his experience.

The second he walked through the door, Hizashi realized it was noticeably colder in the room than it was in the hall. The second thing he noticed was the off and on, inhuman murmurs, coming through the walls and sneaking through the cracks and seams of the building as the students talked amongst themselves. The voice made him freeze just in front of the doorway, and it took someone - Iida - calling his name for him to snap out of it. The class fell silent at the presence of a teacher, and so did the voice.

Hizashi barely managed to make it to Aizawa's desk before the door slid open again. Kaminari rushed in the door three minutes late, greeted the empty air with heya Izuku in a hurry, and made his way to his seat, out of breath, as a tapping sound seemed to come from Kaminari's desk. Kaminari only grinned, not a touch of concern in his features as he sat down. Hizashi was too confused to scold him for his tardiness.

He did roll call. Izuku wasn't on the list.

Hizashi may be silly at times and enjoy joking around, but he was a pro hero for a reason, and knowing how to put two and two together was naturally expected of the profession. These kids weren't telling him outright, but the way they behaved spoke volumes.

Especially Bakugo. He was behaving strangely.

He started the lecture. The room felt odd in a way he couldn't describe, like something was there that wasn't supposed to be, a weird energy lingered in the air, making the hair on his arms and neck stand on end. No matter how many times he scanned the classroom for the perpetrator, he couldn't find anyone that was tapping a pencil or pen, and certainly no one that was standing up to rap their fingernails against the window's glass. Hizashi expected Bakugo to lose it and demand whoever was making the noises to shut the fuck up, but he did no such thing, behaving as though the noises weren't there at all. No one else seemed concerned as Hizashi tried to keep his unease as subtle as possible.

The muttering flickered in and out like a changing radio. No one he could see was speaking, but they were certainly acknowledging it. He could tell Shinsou and Kaminari were splitting their focus on the whispering and his teaching, and when a particularly clear phrase was spoken, they pulled out a separate notebook to jot down their guess on the words. Bakugo himself seemed more intent on listening to the disembodied voice than Hizashi's own, which was an odd sight considering the kid's seriousness when it came to his studies. Asui's eyes flickered around curiously, as if wondering where it was coming from, occasionally looking to the windows when they made the slightest creak.

Yaoyorozu, Todoroki, Mineta, and Tokoyami, despite the room being pleasantly warm, shivered in their seats every once in a while. Hizashi asked them more than once if they would like the heat turned up, but all of them declined, throwing amused smirks and smiles at him, out of all the responses.

What was most interesting, however, was the response his joke got.

Hizashi enjoyed making people smile, and considering the almost somber atmosphere of the classroom, he figured throwing some jokes around would lighten the kids' moods - and his own - at least a little.

He made a simple joke, one he figured the more soft-hearted girls of the class would probably find enjoyable. There was a brief pause, then someone - no, some thing - giggled, the lights briefly flickering as if they would go out. It sounded younger than a high schooler, and it made the class stiffen in surprise. Hizashi tensed, ready for whatever was about to happen next.

The class, however, quickly became ecstatic.

Uraraka and Yaoyorozu gasped, some of the boys laughed breathlessly in a mixture of disbelief and shock, and Bakugo grinned sharply, amused. They talked to each other quietly, laughing and giggling themselves now, and Hizashi had to quiet them down again so he could finish the lecture. The childish response shook him. It sounded young.

After the lecture was done, he gave them free time to start on the homework, and they grouped up immediately. Some groups - most notably the ones including the class rep and vice rep - diligently started on the worksheet in between chatter. Some only pulled out the worksheet for show, not that Hizashi was surprised. Bakugo got to work, keeping to himself, an earbud in to listen to music.

Izuku's name was being brought up again, Hizashi could hear it in multiple conversations. This time the response was decently loud muttering, overlapping and talking over itself, seemingly made up of more than one voice. It seemed to be responding to the occasional prompt from the class, and even though they clearly couldn't understand what was being said, the students reacted positively to it. Hizashi bit his tongue against scolding the students otherwise - if they were this content with interaction then Aizawa most likely condoned it. He wondered if that was a good idea.

When Shinsou asked the presence if it thought Hizashi's joke was funny, amusement coloring his tone, murmurs and laughter was the response. Hizashi shivered.

When class was over, everyone talked to their friends as they packed up. They threw their backpacks on, saying goodbye to Izuku - Bakugo in particular seemed almost sad to leave, grumbling a soft later nerd before reluctantly departing - and leaving the classroom one by one. The muttering resounded until everyone had left, as if replying to each and every goodbye it received, then silenced as abruptly as it had begun, making him clench his teeth in discomfort. Hizashi knew it was still there, hovering, maybe watching.

He packed up his things as quickly as he could without being obvious. Hizashi approached the door to leave, but just before he stepped through he heard a whisper, right behind him, indecipherable but undeniable.

No one was there when he looked over his shoulder. A chill climbed up his spine and made goosebumps prickle at his arms and legs.

He left the room and firmly shut the door behind him, taking a moment to soothe himself and gather his wits before marching down the hall with purpose.

Aizawa had some explaining to do.