Edgar is ill. Nelly takes Cathy out for a walk on the moors to enjoy some fresh air and to cheer her up after ending her little romance. They discuss the possibility of Edgar dying and Cathy announces that she loves Papa and would never "do an act, or say a word to vex him" (22.18). Right.
While out on the walk, Cathy drops her hat over a wall and clambers over to retrieve it. Heathcliff comes up the road and, not seeing Nelly on the other side of the wall, scorns Cathy for sending love letters to Linton and then abruptly stopping. He tells Cathy that Linton is heartbroken and dying and threatens to send the love letters to her father.
Nelly and Cathy return home. Nelly promises to take Cathy to Wuthering Heights the next day.