When a military pilot loses control of his plane and careens into a local bog, he discovers something, or someone, hitched along for the ride. The dark passenger promises to envelop him and the citizens of Ogden Marsh in madness.
A small town in Iowa becomes "Ground Zero" for a cavalcade of Crazies. In an attempt to stop the outbreak in its tracks, the government has quarantined the area, but is it too late to stop the madness from spreading?