Northanger Abbey follows Catherine Morland and family friends Mr. and Mrs. Allen as they visit Bath, England. Seventeen year-old Catherine spends her time visiting newly-made friends, such as Isabella Thorpe, and going to balls.

Catherine finds herself pursued by Isabella's brother John Thorpe (Catherine's brother James's friend from university), and by Henry Tilney.

She also becomes friends with Eleanor Tilney, Henry's younger sister.

Henry captivates her with his view on novels and his knowledge of history and the world.

General Tilney (Henry and Eleanor's father) invites Catherine to visit their estate, Northanger Abbey, which, because she has been reading Ann Radcliffe's gothic novel The Mysteries of Udolpho, Catherine expects to be dark, ancient and full of fantastical mystery.