Nelly ventures back to Wuthering Heights to talk with Hindley; instead she encounters Hareton, who has no memory of her. Hareton greets her with a barrage of stones and curses — actions he learned from Heathcliff. When Heathcliff appears, Nelly runs away.
The next day at the Grange, Nelly witnesses an embrace between Heathcliff and Isabella. When Catherine confronts Heathcliff about this, he tells her "I'm not your husband: you needn't be jealous of me." This leads Heathcliff to reveal that he knows Catherine has wronged him and that he will be revenged.
Edgar confronts both Catherine and Heathcliff. Catherine ends ups locking the door and taunting her husband into a fair fight between Heathcliff and himself. Edgar ends up hitting Heathcliff in the throat and rushes off to get assistance. Realizing he cannot fight three men with weapons, Heathcliff leaves.
Edgar then demands that Catherine choose between Heathcliff and himself. Catherine doesn't answer. Instead, she locks herself in her room, refusing to eat for two days. Unable to get through to Catherine, Edgar informs Isabella that if she were to pursue a relationship with Heathcliff, that action would signify the end of their relationship.
Heathcliff is now acting as both father and teacher to Hareton. This assumption of the paternal role mirrors the way Hindley assumed Mr. Earnshaw's role as father to Heathcliff, and then immediately lessened Heathcliff's status at Wuthering Heights. Now, Heathcliff has taken both Hindley's father and son away from him. Hindley ended Heathcliff's formal education at Wuthering Heights; Heathcliff does the same to Hareton. This is the first part of Heathcliff's master plan for revenge.
After working his way back into Wuthering Heights, Heathcliff aims for Thrushcross Grange, directing the second part of his revenge towards Edgar by encouraging Isabella's infatuation. Heathcliff has no passion, love, or desire for Isabella; he only wants to use her. And he does. Having been so ceremoniously removed from Thrushcross Grange as a child, Heathcliff desires to acquire it, and Isabella supplies the means for him to do this.
Catherine's hysterics followed by her refusal to eat illustrate both her weakening mental and physical self. When she locks Edgar and Heathcliff together and throws the key into the fire, this is the height of romanticism for her. Symbolically, that key represents the key to her heart. She throws it away, and in doing so, actually pushes both men away. Edgar cannot understand her love for someone so crass and wild as Heathcliff; Heathcliff cannot fathom her attraction to the sniveling and weak Edgar. Curiously, Edgar is the one who acts out of character by striking Heathcliff. This action demonstrates the lengths that Edgar will go for the woman he loves.
approbation official approval, sanction, or commendation.
acquiesced agreed or consented quietly without protest, but without enthusiasm.
recriminate to answer an accuser by accusing that person in return; reply with a countercharge.
stolidity the state of showing little or no emotion.
compunction a sharp feeling of uneasiness brought on by a sense of guilt.