In this stage, the protagonist falls under the shadow of a "dark power," and the first paragraph of the story fits the bill nicely. The grandmother brings up The Misfit, a murderer who's apparently on the run. Although she might be using the idea of a murderer as an excuse to vacation in Tennessee, we get the sense that a confrontation with the "dark power" is inevitable.
The family goes on the trip in spite of the grandmother's warnings, and the day is off to a good start. There are those troublesome kids of course, but it seems like a normal family vacation. We are reminded of The Misfit once again, though, when the family stops to eat at Red Sammy's. The discussion between the grandmother and Red Sammy reinforces the idea that The Misfit must be arriving on scene soon.
With the car accident, the grandmother and her family are actually "imprisoned," trapped, in the ditch, waiting for help. Somebody arrives, but it's not help – it's The Misfit. The grandmother reveals that she recognizes The Misfit and things start to look bad.
Things get bad because, The Misfit's cronies start killing off the family members. Eventually, the grandmother is alone and unarmed with The Misfit. She appears to be losing control of herself, despairing, and growing desperate.
The bad news is that the grandmother dies. But this is definitely a "miraculous redemption" – literally. That's why she dies smiling. And the grandmother's "moment of grace" might induce The Misfit to be reborn too.