What are some ominous signs at the beginning of chapter 8?

Nick describes a fog horn as "groaning incessantly" all night so that it prevented him from sleeping soundly; when he did sleep, he felt "half-sick between grotesque reality and savage frightening dreams." Right away, Nick's feelings of sickness and dread seem to foreshadow an ominous future. Daisy has run over Myrtle Wilson while driving Gatsby's car, and Gatsby feels strongly about taking the blame for it rather than allowing Daisy to suffer, but Gatsby didn't see what Nick saw after the accident: Daisy and Tom sitting together over a plate of cold chicken and a couple of beers, talking familiarly and as though Gatsby was never there. When Nick and Gatsby go inside Gatsby's house to look for cigarettes, Nick describes the house as "enormous," with "innumerable feet of dark wall," and he even calls the piano "ghostly." It feels as though these two are lost in a frightening and cavernous place. They seem to grope around blindly as though what was once familiar is no longer, and this creates a mood of foreboding.