Conflict is a necessary part of any story. Without conflict and tension, you’ve got a boring description and no story.
Along with conflict, though, you must have character reaction. If your characters don’t grow and change in response to the conflict, you’ve got another boring story. In order to really hook your readers and keep them rooting for the characters, those characters must react like real people. They must change – even if it is in small ways.
During your story, the characters must reach a point at which they must decide to make that change. This is the Point of No Return. Beyond this point, they can stay the same, go back to their lives as if nothing happened, and “keep on keeping on.”
The Point of No Return is that place in the conflict where the characters cannot react any further without making some sort of change – emotional, spiritual, physical, or mental. And with that change, they cannot “undo” their reaction. They can’t just pretend it never happened and go back to the way they were before.
This is a key part of a good story. Build your conflict to the point where the characters have to make a change, and your readers will follow right along, cheering for the characters. One good way to figure out if your story is progressing properly is to create a number system for your conflict, with 10 being a Point of No Return moment and 1 being no tension at all.
Number your scenes according to the tension and conflict in each one. You should see the numbers increasing until they reach 10. You can certainly have little dips where you slack off on the tension to give your characters a brief rest, but the overall curve should be uphill.
Once the Point of No Return is reached, you should be at or near the action climax of the tale as well – and it’s all downhill from there.