The morning after a violent thunderstorm, a thick unnatural mist rapidly spreads across the small town of Bridgton, Maine, reducing visibility to near-zero and concealing numerous species of bizarre creatures; vaguely resembling, among other things, lobsters, spiders and giant squid, these entities viciously attack any human who ventures out into the open. The source of the fog and its inhabitants is never revealed, but strong allusions are made to an interdimensional rift caused by something known second-hand to the townsfolk as "The Arrowhead Project", which had been long-rumored to be conducted at a nearby top-secret military facility.

This is an old Stephen King book and was the inspiration for Valve Software's Half-Life. The Mist is also believed to be an inspiration for Konami's Silent Hill.