Mrs. Dean describes the twelve years after Catherine Earnshaw Linton's death as the happiest period of her life. Edgar Linton raises young Cathy at Thrushcross Grange with intense tenderness, personally overseeing her education. Cathy grows into a beautiful, affectionate, intelligent child with a gentle nature, though she is also spoiled, saucy, and accustomed to being indulged.

Until age thirteen, Cathy is kept almost entirely within the Grange and its park. Edgar prevents Cathy from learning anything meaningful about Wuthering Heights or Heathcliff, and Cathy remains content except for growing curiosity about the hills and Penistone Crags. Because the road to the Crags passes near Wuthering Heights, Edgar repeatedly postpones Cathy's wish to visit them.

Mrs. Dean then explains that Isabella Heathcliff, after living apart from Heathcliff for more than twelve years, falls fatally ill and writes to Edgar. Isabella asks Edgar to come to her, settle her affairs, say farewell, and take charge of her son Linton. Edgar leaves the Grange for three weeks, ordering Mrs. Dean to watch Cathy carefully and keep her within the park.

At first Cathy grieves over Edgar's absence, but Mrs. Dean begins letting Cathy roam the grounds alone for amusement. Cathy becomes fond of these solitary adventures and, one morning, pretends to be an Arabian merchant crossing a desert, taking provisions, her pony, and several dogs. Cathy fails to return by tea, and Mrs. Dean learns from a laborer that Cathy jumped a low hedge and rode away from the estate, likely toward Penistone Crags.

Mrs. Dean hurries toward Wuthering Heights and finds one of Cathy's injured dogs outside the house. With Heathcliff and Joseph away, the housekeeper admits Mrs. Dean and says Cathy is safe. Inside, Cathy is cheerfully talking with Hareton Earnshaw, now an eighteen-year-old farm-bred youth. Mrs. Dean angrily tries to take Cathy home, but Cathy resists and treats Hareton like a servant, not realizing that he is her cousin.

Hareton angrily curses Cathy, and the housekeeper reveals that Hareton is indeed Cathy's cousin. Cathy is horrified because she believes her only cousin is the gentlemanly Linton whom Edgar has gone to fetch from London. Mrs. Dean worries that news of Linton's arrival may reach Heathcliff and that Cathy will ask Edgar about Hareton. On the way home, Mrs. Dean pieces together that Hareton had guided Cathy to the Fairy Cave and other places after a dog fight brought them together. Mrs. Dean persuades Cathy not to tell Edgar about the visit by warning that Mrs. Dean might be dismissed for negligence.