Every successful story has a sense of direction. The audience wants, and even needs, an idea of where the story is going. If the audience literally has no idea what could happen next, then that often means what happens next doesn't really hold any value one way or another. It's like Willy Wonka's river ride into darkness--confusing, awkward, and a little bizarre. It's hard to trust Willy Wonka to get you anywhere. Writers should avoid being like Willy Wonka, for several reasons.
Wait! you may be thinking. Don't we want our stories to be unpredictable? Isn't not knowing where the story is going more exciting?
Many beginning writers make this mistake (including yours truly back in the day). They think having no clue where the story is going makes it more of a page-turner. They may recall audience members happily describing a story, saying, "I had no clue where it was going!" or "I had no idea what was going to happen next!"
These are just expressions of emotion. In reality, for the audience to even have those emotions, they usually must have a sense of direction first.
It's a similar concept to being vague versus being ambiguous. Vagueness happens when you don't have enough context to tell what something is, if anything. Ambiguity happens when there is enough context to interpret something in two or more ways, and you aren't sure which it is. When audiences say, "I had no clue where it was going," often what they really mean is, "I didn't know which of the critical directions it would go."
A story that has no sense of direction is almost never as effective as one that does. Without a sense of direction, the audience can't measure what is progress or what is a setback. They can't get invested, because they can't anticipate anything. They can't feel tension or suspense or even surprise, because they can't hope or fear for what could happen, and don't have expectations for what is going to happen.
Instead of Willy Wonka's tunnel of terror, imagine taking a hike toward a beautiful waterfall (it can still be made of chocolate if you want). A twisted ankle, closed trail, or nearby predator is a bigger setback than if we had nowhere we were trying to go. A shortcut is a bigger leap in progress if we are trying to reach a specific destination. And discovering we're actually on a trail that leads to an active volcano is a bigger surprise.
There are two critical plot elements that will automatically inject directionality into your story. Then, there are a lot of alternative methods you can use to reinforce it, or that you can rely on when performing a rule break (more on that in a bit). First, let's go over the two major ones:
