Use again.

Argus Filch walked the halls. Now the happiest he’s been in years. He can see these students punished proper. Especially if he can hit that old foolish headmaster with the Ray. Then things will really change for the better.

For now though he was keeping his eyes on the students as he passed. His smug viscous grin never leaving his face. Argus watched for any excuse to punish someone.

Luck was on his side as he spotted a ravenclaw girl. She was using one of those infernal Weasley products. “Oh she would pay dearly for that. Won’t she Mrs. Norris?”