Nearly all of the action in Wuthering Heights results from one or another character's desire for revenge. The result are cycles of revenge that seem to endlessly repeat. Hindley takes revenge on Heathcliff for taking his place at Wuthering Heights by denying him an education, and in the process separates Heathcliff and Catherine. Heathcliff then takes revenge upon Hindley by, first, dispossessing Hindley of Wuthering Heights and by denying an education to Hareton, Hindley's son. Heathcliff also seeks revenge on Edgar for marrying Catherine by marrying Cathy to Linton.
Yet while Heathcliff's revenge is effective, it seems to bring him little joy. Late in the novel, Cathy sees this, and tells Heathcliff that her revenge on him, no matter how miserable he makes her, is to know that he, Heathcliff, is more miserable. And it is instructive that only when Heathcliff loses his desire for revenge is he able to finally reconnect with Catherine in death, and to allow Cathy and Hareton, who are so similar to Heathcliff and Catherine, to find love and marry.