class and social ranking

"Not Mr. Heathcliff, surely?"  This was said on page 159.  Nelly was asking this to someone when she heard that someone else has possession of Wuthering Heights.  It in fact was Heathcliff, and Nelly did not like this idea at all!  She did not trust Heathcliff, and she did have good reasons not to.  Nelly then decided she wanted to return to Wuthering Heights with Hareton.  However, Heathcliff did not allow Nelly to come back.  Rather, he had Hareton stay as a servant to him.  This is a way in which Heathcliff got his revenge.  This has to do with class and social rankings because since Heathcliff was the ruler of Wuthering Heights, he can make people do what he wants them to do, such as work as servants.