In As I Lay Dying, a Southern Gothic novel by William Faulkner, we see disorder, discontent, and rebellion.
Disorder: the novel is told by 15 narrators, totaling 59 narrations, both inside and outside the family, in a non-linear sequence. It is a tour-de-force of disorder: the subjectivity of so many unreliable narrators undercuts the what is true at every turn. Faulkner operates not according to time: he jumps ahead, reverts back, foretells, and retells. He said that there is no distinction between the past, present, and future: we carry the past with us always. "There's no such thing as the past."
Discontent: Addie hates words and her family; Jewel hates his family; Darl hates Jewel: Dewey Dell hates Darl; Anse hates the road and work; Cora hates Addie; Vardaman hates what's in the coffin. All of the psycho-sexual problems related to death, family, and the haunted South are present in this novel. Everyone is a grotesque: injured emotionally, physically, or mentally.
Rebellion: Addie was a nihilist: her death is revenge against her own family, as she knows they will suffer during the journey. The novel is a rebellion of words; it is language that attacks language and the nature of truth. Faulkner rebels against time, narration, objectivity, death, and the tragic and comic conventions of the novel. As I Lay Dying is truly subversive literature.
Gothic fiction is all about horror, illogic, imagination (especially dark, melancholy) and emotion. Some scholars think that the Gothic era was in response, a rebellion against the reason of the Enlightenment. Taking place during a time of great revolutions (American and French), the idea of rebellion during the height of the Gothic era was definitely in the air.
The example I usually refer to is Mary Shelley's Frankenstein.This novel combines a lot of Gothic elements and it also is one of the first works of science fiction. Since Gothic fiction was a rebellion against reason, it is also a critique of the growing power of science as the objective practice. With Frankenstein, we have a scientist who's rationality actually leads to horror instead of beauty. This is also an example where the idea of the sublime shifts from ideal and structured to wild and unreasonable.
In general, Gothic fiction is horror/mystery; but it comes from ideas during a revolutionary age and those ideas also came from the growing emphasis on science, order and reason and the convergence of ideas like Reason vs. Emotion, Science vs. Spirituality, Madness vs. Vision, Natural vs. Supernatural, and Chaos vs. Order.