To me, the horror of the book came fairly early on. Not so much from the events of the story, but the implications of it, and how certain concepts resonated with my own thoughts and experiences in life. More psychological horror than overt, I suppose.

I'm not someone who gets scared easily by fiction, it's been a long time since anything had done it for me, but House of Leaves left me genuinely uncomfortable/looking over my shoulder more than once. The style of the writing definitely contributed to that as well, having to change the way I read it made me feel way more immersed in the material.