Hundreds of years from now, the last surviving humans discover the means of sending consciousness back through time, directly into people in the 21st century. These "travelers" assume the lives of seemingly random people, while secretly working as teams to perform missions in order to save humanity from a terrible future.

Four interwoven stories that occur on Halloween: an everyday high school principal has a secret life as a serial killer; a college virgin might have just met the one guy for her; a group of teenagers pull a mean prank, and a bitter old recluse receives an uninvited guest.

Christy returns to her hometown years after a car accident that disfigured her older sister. Haunted by the accident in which she was the driver, she learns that her worst nightmares have either come true... or are about to.

A group of teens journey to a remote cabin in the woods where their fate is unknowingly controlled by technicians as part of a worldwide conspiracy where all horror movie clichés are revealed to be part of an elaborate sacrifice ritual.

Dr. Adrian Helmsley, part of a worldwide geophysical team investigating the effect on the earth of radiation from unprecedented solar storms, learns that the earth's core is heating up. He warns U.S. President Thomas Wilson that the crust of the earth is becoming unstable and that without proper preparations for saving a fraction of the world's population, the entire race is doomed. Meanwhile, writer Jackson Curtis stumbles on the same information. While the world's leaders race to build "arks" to escape the impending cataclysm, Curtis struggles to find a way to save his family. Meanwhile, volcanic eruptions and earthquakes of unprecedented strength wreak havoc around the world.