Nia jumped at the loud noise, before straightening herself back up again and fiddling with her quill.

"I agree with Celandine," she said, tucking some hair back that had strayed forward when she jumped. "Something based on distractions and hiding or concealling things." She paused. "Like you appeared from nowhere, which I assume was a disillusionment charm, and then you distracted us by making us all turning our gaze to the ceiling even though there was nothing obviously there. Once we were staring up there trying to find what you were looking at, it was quite possible that you did something else. Like conjure loud noises." She tried giving him a hard stare after mentioning the loud noises - but it wasn't possible. Professor Ashby was one of her favourite professors, and he just had one of those jovial likeable personalities.