After Ron criticises Hermione's ostentatious proficiency in Charms, she hides in the girls' toilet, crying. At the Halloween Night dinner, Professor Quirrell reports that a troll has entered the dungeons. While everyone returns to their dormitories, Harry and Ron rush to warn Hermione. The troll corners Hermione in the toilet but Harry and Rone clumsily save her. Afterwards, Hermione takes the blame for the battle and becomes a firm friend of the two boys.