For 'The Fall of the House of Usher', it's the decay and the sense of inescapable doom. The house is like a living entity that is slowly dying and taking its inhabitants with it. The incestuous undertones between the Usher siblings also add to the overall sense of unease and horror.
The most terrifying element is often the sense of the unknown. In poe's stories, things are not fully explained. For example, a strange noise in the attic, but you don't know what's causing it. It plays on our fears of the unseen and the unknowable.
Another very scary Poe story is 'The Fall of the House of Usher'. The gloomy atmosphere of the decaying Usher mansion, along with the strange malady of the Usher siblings, creates an air of doom. The story is filled with a sense of impending disaster from start to finish, and the final collapse of the house is both a physical and a psychological cataclysm.
One element is the unknown. In many of these stories, like in 'The Call of Cthulhu', there are things that are beyond human understanding. The idea that there are forces or beings out there that we can't fully comprehend is really frightening. Another is the sense of isolation. For example, in 'The Shining', the family is stuck in an isolated hotel in the middle of winter, cut off from the outside world. It makes the danger seem more intense.
In Poe's ghost stories, the atmosphere is one of the scariest elements. For example, in 'The Fall of the House of Usher', the decaying mansion with its dank and dark interiors creates a sense of foreboding. The description of the house makes it seem like a living entity itself. Another scary element is the characters' psychological states. In 'Tell - Tale Heart', the narrator's insanity and his obsession with the old man's eye are terrifying. His paranoia that the old man's heart is still beating under the floorboards is a very disturbing aspect.
One of the scariest elements is the sense of helplessness. When students got locked in a room in the old castle during a school trip, they couldn't do anything to get out immediately. Another is the fear of the dark. In the museum when the power went out, the darkness made the situation much scarier. And the fear of wild animals, like the bear at the campsite during the camping school trip.
The sense of betrayal can be really scary. When you expect a product to be safe or a service to be reliable on 3 15 (a day associated with consumer protection), and instead you get something that causes harm or distress. It's like being tricked by the system. For instance, if you buy a food item thinking it's fresh and healthy but it makes you sick. It makes you question everything you thought you knew about consumer safety.
I think the story about the shape - shifting monster might be the scariest. It can take on different forms, so you never really know what it looks like or where it is. It could be lurking around you as a harmless - looking animal one moment and then turn into a terrifying beast the next. It plays with your mind and your sense of safety. Plus, in the story, it always seems to target the most vulnerable people, like children or the elderly.
The darkness is one of the scariest elements. In catacombs, it's often pitch - black, and you can't see what might be lurking. Another is the sense of isolation. When you're deep in the catacombs, you feel cut off from the outside world. And the unknown history also adds to the scariness. You don't know what tragedies or horrors might have occurred there in the past.
The unknown is a very scary element. In Wiccan stories, there are often mysterious powers and spells that we don't fully understand. For example, a spell that can make people see things that aren't there.
The unexpectedness. For example, a character thinking they're alone then suddenly a face at the window. It gives a shock.