Unable to return to sleep, she leaves her husband Neil slumbering in bed and goes downstairs to work on a manuscript in progress.

They decide to flee their isolated home, gathering with the residents of the nearby small mountain town, in order to prepare a resistance, though they are not even sure against what they will be fighting.

Peculiar fungi appear in the restroom of a local tavern, and a frightening fungus grows upon trees, lawns, houses, and people alike.

Molly and Neil, accompanying a stray dog named Virgil, set off on a mission to rescue the town’s children, many of whom are trapped in their homes.

As they search for answers, the townspeople conclude that they are under siege by extraterrestrial invaders who have come as an advance party to reverse-terraform the Earth so that its altered atmosphere will support their alien physiological needs.

At all times, while they encounter the most horrible and twisted creatures during their journey, Molly senses that the invaders are of the most malignant kind, and that they want nothing but destruction.

In 2006, it was announced that Sam Raimi's Ghost House productions had purchased the rights to this book and planned to do a miniseries based on it for their new television banner.