Grace Hanadarko is an Oklahoma City detective who investigates major crimes. However, she also leads a reckless lifestyle that can get her into trouble.
When she runs over and kills a pedestrian while drunk, she cries out for God's help. It is then when she meets her guardian angel in the form of a rough-around-the-edges man named Earl.
Earl informs Grace that she's going down the road to Hell, unless she's ready to turn her life over to God. When Earl disappears, the person she struck has also vanished and it's as if the accident never took place.