Four men are changed forever by an act of mercy -- changes which have a profound impact many years later -- in this blend of horror and science fiction based on a novel by Stephen King. Jonesy (Damian Lewis), Henry (Thomas Jane), Pete (Timothy Olyphant), and Beaver (Jason Lee) were four friends who, as schoolboys, rescued a boy with Down's Syndrome, Duddits (Donnie Wahlberg), from a savage beating at the hands of bullies. Their experience with Duddits left the boys profoundly changed, as they discovered they had developed psychic powers which allowed them to wordlessly communicate with one another, read the minds of others, and see events in the future. The four remained close friends into adulthood, and meet every year for a weekend get-together at a remote hunting lodge. However, one year Jonsey is approached by the spirit of Duddits, which leads him into a severe auto accident, though his wounds heal with mysterious speed and are gone by the time he and the guys get together a few months later. As the guys drink and swap stories, a desperately ill hunter makes his way into the cabin, whose body has become the host for a horrible wormlike creature, which breaks free and soon goes on a killing spree, leaving only Henry alive. In the wake of this attack comes a massive snowstorm, and Henry learns that these events are the first signs of a major attack by a powerful alien force which can assume any form it wishes. As duplicitous military leader Col. Abraham Curtis (Morgan Freeman) comes in to quell the menace, Henry finds himself in communication with the late Jonsey, whose previous near-death experience gives him an unexpected advantage in stemming the alien tide.