Suspense

Suspense is "a state of anxiety or excitement caused by mysteriousness, uncertainty, doubt, or undecidedness." In narrative the article splits it into two kinds. In the first the outcome is genuinely open, and "the suspense resides in the question of who, what, or how." In the second the result is already fixed by earlier events, and "the suspense resides in the audience's anxious or frightened anticipation in the question of when." The article also records the paradox of suspense: repeat audiences who know the ending still feel the tension, on theories ranging from forgotten details to fictional immersion overriding factual knowledge.

That split is a planning tool. An open-outcome story, such as a mystery, spends its pages hiding the answer; an inevitability story, such as a tragedy or a thriller with a shown ending, spends them making the reader dread an arrival they cannot stop. The genre that runs on this mood is covered in how to write a thriller, and in serialized fiction the cliffhanger is suspense compressed into the gap between chapters.