In "Wuthering Heights" how do Lockwood's dreams add to the mystery amd gloom of the novel?

Lockwood's dreams set up the mystery of who Catherine Earnshaw Linton really was. They also heighten and foreshadow some of the cruelty that is evident in later parts of the book. For instance, Lockwood rubs the wrist of Catherine's ghost across a pane of glass so she will let go of him. The supernatural elements of his dreams also add to the Gothic mystery surrounding Wuthering Heights. They also heighten the tension in the novel which is initially established with Lockwood's arrival and his strange treatment by Heathcliff. All of these occurrences eventually lead Lockwood to try to solve these mysteries by asking Nelly Dean about Heathcliff and that leads to her narrative of the rest of the story.