“Harry — I think I've just understood something! I've got to go to the library!”
And she sprinted away, up the stairs.
“
What does she understand?” said Harry distractedly, still looking around, trying to tell where the voice had come from.
“Loads more than I do,” said Ron, shaking his head.
“But why’s she got to go to the library?”
“Because that’s what Hermione does,” said Ron, shrugging. “When in doubt, go to the library.”
―
J.K. Rowling,
Harry Potter and the Chamber of Secrets