Three years after a tragic accident leaves a student dead at the annual Homecoming dance, a group of senior friends anxious about the return of Homecoming Night to their sleepy Southern town find themselves visited by a deadly presence from their past in the dark and desolate halls of their very own high school.
When a colossal tectonic shift causes the sea level to start rising, a microbiologist gathers the DNA of as many species as she can, while the military creates an "ark" in a desperate attempt to preserve life on Earth.