What makes a good horror story? What scares you?

What makes a good horror story? What scares you?

For me, the basic characteristics of a good horror story don’t differ much from any other kind of story: I want to be able to visualize the setting and feel the tension. If I can ‘see’ the scene, I feel immediately connected to the story, and if the angst of the characters resonates, I feel invested.

Horror, of course, has to include the threat of death to the main character as a result of someone or something malevolent. So, in addition to setting and tension, any good horror story has to include a terrific monster.