About horror elements. What's it called?

[Kreekakon]

I think the thing that you're most closely thinking about is something I believe is called something along the lines of "mid-act climax"

It is when the plot of a piece reaches a very hot boiling point similar to a climax (But made out so that the story is obviously not over yet). After the climax resolves...repercussions of said climax will feed into the next act of the story altering it somewhat large or small for the rest of the story.