“This is what happened on the night that the worst heat wave in northern New England history broke—the night of July 19—the entire western Maine region was lashed with the most vicious thunderstorms I have ever seen.
The story narrator, David Drayton, tells what else happened. He and his wife and son Billy lived on Long Lake, and about an hour before dark, they saw that a bad storm was on the way, just rolling across the lake towards them. The storm raged through the night and did more damage than David, the second generation on the property could ever remember happening before.
The following day the storm had stopped, and the sky was blue, but a dense mist had settled on the lake and seemed to be moving slowly towards them. Some thought the fog might have come from the direction of a local military facility, but it came on the heels of the storm.
The mist seemed to have sharp edges and looked a little like a cloud. David and Billy go into town to get supplies when Norton, a neighbor, shows up and goes with them.
When they reach the town, they find themselves trapped in the local supermarket with a small group, all survivors of the storm needing help. The mist emerges and has hidden within it unnatural forces that want to kill them in terrifying ways. Trapped in the supermarket, the people turn on each other and struggle to find a way to escape the threats from both within and from the mist.
A scary story from the master of scary stories, Stephen King