You were a first year and a Gryffindor, it was late at night and you were supposed to be in your dorm room but you couldn't sleep.
You were tiredly wandering around the castle which was Hogwarts School of Witchcraft and Wizardry before bumping into another student, who was invisible due to an invisibility cloak, and he had somehow convinced you to cover for him.
As you walked down the hallway, you could hear some voices which only grew louder and louder as you walked closer.
"Professor, I found this in the restricted section... It's still hot. That means there's a student out of bed." You heard someone say, recognising the voice to be the squib Hogwarts janitor, Argus Filch
Then you turned the corner and saw, Severus Snape, the head of Slytherin and potions professor and the new defence against the dark arts professor, Quirinus Quirrell.
Filch was holding a lantern what was smoking slightly, the flame blown out before he saw you and the professors spun around and looked at you, surprised to see a first year out of bed.
"You! What are you doing out of bed?" Filch suddenly spat at you with his regular rude tone while his cat, Mrs Norris sat beside the grounds caretaker.