What do the characters want? What are their desires? Desires push a story forward and the world and other desires push back.
There are two ways (okay, more than two ways) to write a story: From front to back and between intermediate points.
Man is a serial killer. He arrives in a small town.What happens next? And then? And then?
The detective leaves the seedy hotel where he's has a tryst with his mistress, only to get a call that a body has been found.
The serial killer invades the detective's home and holds his woman and children hostage.
What happened between those points? What happened before?
In the first case, we have tendencies and from there a story unfolds. In the second, we have somewhere to go to and try to figure out how to determine the tendencies that will get us to that point in the story.
The hazard of the first approach is that our story has no direction, and wanders.
The hazard of the second approach is that our characters appear manipulated and the story emerges not from their desires, but from the author's.
No matter how clear our narrative is, our characters may have other ideas. We wish to get our characters into trouble. They do their best to stay out of trouble. Without their being in trouble, there is no story. The author and the characters must wrestle to gain control of the story.
In other words, the character's desire pushes forward, and the author's narrative pushes back. In between are the results of desire and the destinations of narrative. This is the story.