At last, Catherine permits the servants to bring her food. Hysterical, she believes that she is dying, and cannot understand why Edgar has not come to her. She rants about her childhood with Heathcliff on the moors, and speaks obsessively about death. Nelly, worried that her mistress will catch a chill, refuses to open the window. Catherine manages to stumble to the window and force it open; from the window, she believes she can see Wuthering Heights. Catherine says that even though she will die, her spirit will never be at rest until she can be with Heathcliff. Edgar arrives and is shocked to find Catherine in such a weak condition. Nelly goes to fetch a doctor. The doctor professes himself cautiously optimistic for a successful recovery.
That very night, Isabella and Heathcliff elope. Furious, Edgar declares that Isabella is now his sister only in name. Yet he does not disown her, saying instead that she has disowned him.
Edgar and Nelly spend two months nursing Catherine through her illness, and, though she never entirely recovers, she learns that she has become pregnant. Six weeks after Isabella and Heathcliff’s marriage, Isabella sends a letter to Edgar begging his forgiveness. When Edgar ignores her pleas, she sends a letter to Nelly, describing her horrible experiences at Wuthering Heights. In her letter, she explains that Hindley, Joseph, and Hareton have all treated her cruelly, and that Heathcliff declares that since he cannot punish Edgar for causing Catherine’s illness, he will punish Isabella in his place. Isabella also tells Nelly that Hindley has developed a mad obsession with Heathcliff, who has assumed the position of power at Wuthering Heights. Hindley hopes that somehow he will be able to obtain Heathcliff’s vast fortune for himself, and he has shown Isabella the weapon with which he hopes to kill Heathcliff—a pistol with a knife attached to its barrel. Isabella says that she has made a terrible mistake, and she begs Nelly to visit her at Wuthering Heights, where she and Heathcliff are now living.
Nelly grants Isabella’s request and goes to the manor, but Edgar continues to spurn his sister’s appeals for forgiveness. When Nelly arrives, Heathcliff presses her for news of Catherine and asks if he may come see her. Nelly refuses to allow him to come to the Grange, however, and, enraged, Heathcliff threatens that he will hold Nelly a prisoner at Wuthering Heights and go alone. Terrified by that possibility, Nelly agrees to carry a letter from Heathcliff to Catherine.
Heathcliff, who seemed an almost superhuman figure even at his most oppressed, emerges in these chapters as a demonically charismatic, powerful, and villainous man, capable of extreme cruelties. Tortured by the depth of his love for Catherine, by his sense that she has betrayed him, and by his hatred of Hindley and the Linton family for making him seem unworthy of her, Heathcliff dedicates himself to an elaborate plan for revenge. The execution of this plan occupies much of the rest of the novel.
Though Heathcliff’s first reunion with Catherine seems joyful, Nelly is right to fear his return, for he quickly exhibits his ardent malice, first through his treatment of the pathetic wretch Hindley, and then through his merciless abuse of the innocent Isabella. But though his destructive cruelty makes him the villain of the book, Heathcliff never loses his status as a sympathetic character. Although one can hardly condone his actions, it is difficult not to commiserate with him.