Nelly pauses in her narrative to tell Lockwood that the events she's now describing took place a little over a year ago during the previous winter. She notes how odd it is to be telling the story to a stranger, though she wonders if Lockwood might fall in love with Cathy and thereby cease to be a stranger. Lockwood agrees that he just might fall in love with Cathy, but adds that she's unlikely to return the feeling and that, anyway, he'll have to leave soon because the moors aren't his home. He asks Nelly to continue the story. She does.
The fact that the narrative has nearly caught up to the present makes the story feel much more immediate. Also important is that Lockwood recognizes himself as a man of the city rather than of the moors, and he sees this as an obstacle to any possible love he might share with Cathy. In other words, he sees that his civilized life has no place in the harsh moor country that is Cathy's home.
Obeying her father's wishes, Cathy ceases to visit Linton. But Linton also does not visit the Grange because he's too weak to make the trip. Eventually Edgar decides that his daughter's happiness is most important and he says that if she wishes Cathy may marry Linton, even though that would mean Heathcliff would definitely inherit the Grange.
Edgar gives up fighting against Heathcliff, realizing that it brings only more misery.
As he falls further into illness, Edgar agrees to let Cathy visit Linton, though he asks that she meet him not at Wuthering Heights but on the moors. However, Nelly further explains to Lockwood, Edgar didn't know that Linton was almost as close to death as Edgar himself.
If Linton were to die before Edgar, then Thrushcross Grange would go to Cathy after Edgar died. But were Linton and Cathy to marry, Heathcliff would gain control of the Grange after Edgar died.