Getting lost in unknown places. For example, if you end up on a train that goes to some remote area, you might be in a place where there's no help available. You could be in a desolate area with no food or water, which is really terrifying.
The danger of getting injured. Just like I said before, misjudging the jump can lead to getting dragged or hit by the train.
A traveler once hopped on a train not realizing it was headed for an abandoned part of the railway. As the train moved further, there were no signs of civilization. The area was desolate. He started to run out of food and water. The loneliness and the fear of being stranded in such a remote place haunted him. He had to wait for days until another train came by in the opposite direction to get him out of that nightmare.
The sense of mystery is a big part of it. In these stories, there are often no clear explanations for the hauntings. For example, the phantom passengers who seem to come and go without a trace. It makes the whole situation very spooky because there's no way to predict or understand what's going on. Also, the association with the train itself. Trains are usually places of transit and safety, but in these stories, they become places of horror. It's a contrast that makes the stories even scarier.
The unknown is the scariest. In 'as is horror stories', things are often left in their natural state, so you don't really know what's lurking in the shadows or what's causing those strange noises. It's that sense of not having all the answers that makes it terrifying.
Isolation is also a key element. When characters are alone in a spooky place, like an abandoned asylum in one of the stories. They have no one to turn to, and that makes the situation even more terrifying as the horror unfolds around them.
The unknown is one of the scariest elements. When things are not clearly defined, like a strange figure in the fog in some stories from '1001 horror stories', it makes our imagination run wild. We start to create the most terrifying scenarios in our minds.
The scariest element could be the sense of the unknown. For example, in many stories, there are strange noises or happenings that the characters can't explain. It's that not - knowing what is causing the fear that really gets to you.
The isolation in many of the stories is really scary. Like when a character is alone in an old, abandoned building, cut off from the outside world, and they start to feel like they're being watched by something malevolent. There's also the fear of the supernatural, such as ghosts or demons that defy the laws of nature. This makes the characters, and the readers, feel powerless against them.
The sudden movement of the LPS toys when they're not supposed to be able to move is really scary. It goes against what we know about them as inanimate objects.
The unknown and the supernatural. Take the Black Shuck for instance. A huge, black spectral dog just appearing out of nowhere is terrifying. There's no rational explanation for such a thing, and that's what makes it so spooky in UK horror stories.
The loss of control. When someone is hypnotized, they are in a vulnerable state. In horror stories, this often means they can be made to do things against their will, like harming themselves or others, which is really scary.