In Arborville, California, three high school students try to protect their hometown from a gelatinous alien life form that engulfs everything it touches.
A rogue scientist near a small desert town arouses the suspicion of the town's doctor when his lab assistant is found dead from a case of acromegaly, which took only four days to develop. As the doctor investigates, aided by the scientist's new female assistant, they discover that something is devouring local cattle and humans in increasingly large quantities.
After a violent storm, a dense cloud of mist envelops a small Maine town, trapping David Drayton and his five-year-old son in a local grocery store with other local residents. They soon discover that the mist conceals deadly horrors that threaten their lives, and worse, their sanity.
Five years ago, a tear in the fabric of reality brought creatures to our world from an alternate dimension bent on our destruction. A father hides his daughter on an island to keep her safe while he prepares her for survival and the battles to come. But when the world is about to break, no place is safe.
As a result of nuclear testing, gigantic, ferocious mutant ants appear in the American desert southwest, and a father-daughter team of entomologists join forces with the state police officer who first discovers their existence, an FBI agent and, eventually, the US Army to eradicate the menace, before it spreads across the continent — and the world.