On their way down to the Great Hall for the Halloween feast, Harry and Ron overheard Parvati Patil telling her friend Lavender that Hermione was crying in the girls’ bathroom and wanted to be left alone. Ron looked still more awkward at this, but a moment later they had entered the Great Hall, where the Halloween decorations put Hermione out of their minds.
A thousand live bats fluttered from the walls and ceiling while a thousand more swooped over the tables in low black clouds, making the candles in the pumpkins stutter. The feast appeared suddenly on the golden plates, as it had at the start-of-term banquet.
Harry was just helping himself to a baked potato when Professor Quirrell came sprinting into the hall, his turban askew and terror on his face. Everyone stared as he reached Professor Dumbledore’s chair, slumped against the table, and gasped, “Troll — in the dungeons — thought you ought to know.”
He then sank to the floor in a dead faint.
(Harry Potter and the Philosopher’s Stone)