At the girl's question, she shivered. "I certainly hope it is just the Entrance Hall, or possibly a few more corridors. I would rather not find my dormitory soaked."
Belinda was starting to feel distinctly uncomfortable. Honestly, you'd think there would be a teacher or prefect or someone else she could shove this job onto. But as this girl seemed to expect her to help, she couldn't just leave. Not without appearing unforgivably rude. Especially as she seemed to be trying to be so bloody nice.
Her thoughts resulted in a quizzical expression, and a "we could always leave and get Filch to deal with it."