A quiet morning in a small town, a mysterious bank of fog suddenly descends, plunging the community into uncertainty. After a violent storm, David Drayton, a local artist, heads to the grocery store with his son, Billy, and their neighbor, Brent, to stock up on supplies. However, what begins as a simple trip quickly turns into a nightmare when the fog brings with it monstrous creatures that attack anyone who dares to venture outside.
Trapped inside the store, the customers are forced to confront both the terrifying beings lurking outside and the human tensions that arise among them. As paranoia and fear escalate, different factions begin to form, from those suggesting a rational approach to those who believe the fog is divine punishment, led by a fervent religious zealot.
The situation quickly devolves into a struggle for survival, and David, determined to protect his son, seeks a way out as the atmosphere grows increasingly oppressive. As scarce resources dwindle and madness takes hold of those trapped inside, the film addresses not only the tangible horror of the creatures but also the psychological terrors that emerge when civilization faces the unknown. A harrowing exploration of human nature in the face of despair and fear.