The rules for different kinds of writing seem to favor dividing a write-up into three parts. In humor writing, there is the setup, the delay, and the punchline; in academic and business writing, there is the opening, the middle, and the closing. And narrative fiction follows this tradition in the three-act structure, the oldest storytelling structure, popularized by Aristotle. This structure divides a story into three parts, the Setup, the Confrontation, and the Resolution.

The Setup. This act is the second-longest of the three parts. It usually begins with the exposition; it introduces the characters, explaining how they relate to one another, and describing the world around them. Shortly after, something happens in the protagonist's world, signaling that his life is about to change forever. We call this occurrence the inciting action. It further brings about the first plot turn — a more dramatic event occurring when the protagonist addresses the inciting action — which brings the first act to an end and raises the dramatic question the story intends to answer. Every fictional narrative ends when it answers the dramatic question; like will A win the competition, will X win Y's heart, will Z find see his lost relative again. This question propels the story forward and keeps readers engrossed. 

The Confrontation. This act is the longest of them all. It typically continues from the end of the first act, with the protagonist trying to handle the heat brewing from the first plot turn — this is the rising action — only for things to worsen at the midpoint. It becomes clear that the protagonist isn't aware of what he has gotten into, neither does he have what it takes, and he needs to prepare better for the challenges ahead. A good midpoint drama threatens the success of the protagonist's adventure, making him aware of his inadequacies, which he then decides to tackle. Here, at the second plot turn, he becomes more proactive and ready to do whatever it takes. The second act raises the stakes for the protagonist, who, at the midpoint, has invested himself deeply into his mission; the changing process in his character arc is beginning, and with the help of other characters, his prospects for success seem likely.

The Resolution. This part begins with "The Dark Night of the Soul," or the pre-climax. Here the main character gets his first face-off with the antagonist, who delivers a critical blow to the protagonist. This temporary defeat brings the protagonist to his lowest point of fear and despair throughout the story. This point often destroys all existing hopes of success and raises the suspense level above the ceiling, as the protagonist's success hangs in the balance. Next, the protagonist bounces back — the climax. This decisive moment is usually shorter than the pre-climax. And here is where readers witness the final efforts of the main character; he has to reach the peak of his potential to solve the conflict. Finally, we get to see the result of everything the protagonist has gone through in the denouement. This closing act answers the dramatic question of the story, releases the tension, and ties up all the loose ends. Readers also learn who the protagonist becomes after all is said and done.