Soon, Hermione discovers exactly what the monster of the chamber is and how it's travelling. She wen tot the library before the Quidditch match. There she told the first person she met, Penolpe Clearwater to have a mirror when turning corridors. They both saw the basilisk in the mirror and were petrified for the rest of the year. Even petrified Hermione helped the boys, they used the paper with her research to find the chamber and save Ginny.