Catherine Morland, daughter of a rural clergyman, is a spirited tomboy with a passion for Gothic novels. In Bath for the season with family friends, Catherine makes the acquaintance of the vivacious Isabella Thorpe and her flirtatious brother John, who soon has designs on Catherine.

However, her head is turned by Henry Tilney, a gentle young man with a good sense of humour. His father, General Tilney, invites Catherine to stay at Northanger Abbey, the medieval family home.

Allowing her gothic imagination to run wild, Catherine conjures up a murder mystery surrounding the death of the General's wife several years earlier. Henry cathces her looking for evidence in locked rooms and is offended by her mistrust.

General Tilney, realising Catherine's parents are more humble than wealthy, forbids Henry to have any further to do with her. Catherine is expelled from the house, devastated that she has offended her hosts. Yet Henry cannot get Catherine out of his mind. Disobeying his father, he follows Catherine to her home to reveal his true feelings.