The Mist is the descriptor for an abnormally thick, unnatural mist inhabited by various species of otherworldly creatures and predators, believed to be from another dimension.
In the novella, The Mist lasted for three days and presumably even longer. It is not specified whether the mist was contained to an amount of the country or spread across the planet.
In the film, about three days after the mist engulfed Bridgton, Maine and the surrounding area, the creatures were exterminated by the military, and the mist dissipated for reasons unknown.
In the novella, the mist is white, has an acrid smell, and warps acoustics, causing close things to sound far away and vice versa. It also darkens to grey at night. It seems to allow for a smaller field of vision than the Film.
In the film, the mist is a matte grey-chrome color and apparently does not warp acoustics. It also turns a dark blue at night, and it is never stated in the film to have an acrid smell.
In the television series, the Mist features similar physical properties to both the film adaptation (grey color, blue at night) and the novella (warped acoustics). However, its effects are wildly different from both the film and the original novella. Rather than acting as a kind of ecosystem for creatures from another dimension, the Mist in the television series appears to manifest physical entities and anomalies that represent the darkest and most troubled parts of its victims' psyche. Most often, the "creatures" that the Mist manifests correlate to a person's deepest fears, though in some cases they seem to correlate more with a person's repressed memories or physical/mental trauma that the person has suffered. The "creatures" that manifest within the Mist are almost always hostile, killing both humans and animals in brutal, often-gruesome fashion. It is currently unknown how the Mist is able to manifest a person's darkest fears and memories into physical form.
Theories and evidence throughout the novella and the film suggest that the Mist is an alternate dimension which poured into our own when The Arrowhead Project went awry. This theory is supported by the fact that the Mist originated in Shaymore (which is where the Arrowhead Project took place) and there was a large amount of police and military forces heading towards Shaymore at the time when the mist appeared.
In an early draft of the script for the 2007 film, it was revealed that the Arrowhead Project did indeed cause the mist. During the storm, the personnel at the base were able to successfully open a portal to another dimension. However, lightning from the storm struck the base, causing the machinery to overload, and the Mist and the creatures inhabiting within it to pour through the portal.
The Mist is inhabited by a large number of species, all of which hunt on the basis of Smell (as the Mist makes sight almost useless to them), but some of which can also be attracted to light. Most, but not all of the creatures are only active at night. They include:
- Tentacles from Planet X
- Gray Widowers
- Killer Kites (novella only)
- Green Flies (novella only)
- Giant Spider Creatures (film only)
- Other Creatures
- As it is very similar in both inhabitants and appearance, some Stephen King fans believe that the Mist is the Todash Darkness from Stephen King's Dark Tower series - a monster-filled void between universes.
- In the original script for the film, a prologue scene showed the military personnel at the Arrowhead Project base opening an interdimensional portal that allowed the mist and the creatures in it through into our dimension. However, this scene was scrapped to leave the origins of the Mist more ambiguous.
- Very similar creatures to the ones inhabiting the mist appear in another Stephen King novel, From A Buick 8. They die and turn to sizzling, black liquid outside of their world, just like the Tentacles from Planet X in the film, and are also believed to come from another dimension; possibly the same one.
- Several reference to the Great Blizzard of 1888 are made within the novella, as both were heavily clouded events (Blizzard and Mist respectively) that affected the Eastern Seaboard.