What crime was this that lived incarnate in this sequestered mansion, and could neither be expelled nor subdued by the owner? – what mystery, that broke out now in fire and now in blood, at the deadest hours of night? What creature was it, that, masked in an ordinary woman’s face and shape, uttered the voice, now of a mocking demon, and anon of a carrion-seeking bird of prey?

– Charlotte Bronte

Jane Eyre, Chapter 20. Jane asks herself this as she watches the injured body of Richard Mason, who has been stabbed and bitten in the middle of the night. She wonders what manner of mysterious creature with its demonic scream and wearing a woman’s face is prowling the halls of Thornfield. Jane will later learn that the bed burning incident and wounding of Richard Mason were carried out not by a demon, but by Rochester’s insane wife Bertha. She is cloistered in the highest place within Thornfield Hall.