Vampires are a relatively common trope/thread in the Gothic genre that contributes to the terror and horror of the novels that they are present in. The Gothic novel follows a plot of suspense and mystery, which is apparent throughout the novel. We are also able to see the decaying state of the country due to the vampires essentially taking over the city at night where Neville lives. It is gloomy because of the vampires, but it is also gloomy because of Neville's outlook on the apocalypse that happened. Neville is going mad from the chaos that is surrounding him, and it is expected that he would have continued to go even more mad if he did not meet his demise at the end of the novel because he was spiraling into madness through his drinking problem.
The vampires show and symbolize the change that the world had went through. The characters in the novel receive no explanation as to why they are going through the things that they are going through. Neville is the last living human on this terrible Earth that was created, and is completely removed from any human interaction. The most interesting form of terror that deviates slightly from the Gothic novel and moves more towards horror is the turn towards psychological horror. There is less of a monstrous aspect, even though it is still there, and a move towards going through the psyche and terror that the protagonist feels in response to the monsters that he faces in his daily life.
