A pandemic of unknown cause is spreading across the northeast of the US, mysteriously within well-defined borders. Victims experience loss of speech and physical disorientation; they freeze, and then unfreeze to commit suicide: people jump from buildings, shoot or hang themselves, one feeds himself to lions in the zoo, some cut themselves with a hairpin, barbed wire, glass, or a grass mower, drive into a tree, etc. The protagonist, a science teacher named Elliot Moore (Mark Wahlberg), flees together with his estranged wife, Alma Moore (Zooey Deschanel) and the eight-year-old daughter Jess (Ashlyn Sanchez) of Elliot's best friend, Julian (John Leguizamo), who is trying to reach his wife. The rest of the film follows them on their journey. They travel by train until the train stops at a small station, and train services are discontinued. Then they get a ride, and after that proceed on foot.
Elliot deduces that plants and trees produce an airborne neurotoxin when the number of people that are present is larger than a threshold, and also that this threshold is decreasing with time.[1] Finally even isolated people are affected. Eliot and Alma prepare to die, but the pandemic is suddenly over. They adopt Jess, whose parents have died. Three months later there is a new outbreak in Paris.