The walking dead have taken over the world and only a small band of the living survive. This motley group of scientists and soldiers are barricaded in an abandoned missile silo where the chief scientist is conducting grotesque research experiments to find a way of controlling the ravenous, marauding zombies. Tensions meanshilw become intolerable, especially when the self-appointed psychotic military leader discovers that sone of his soldiers have been used as guinea pigs in the zombie experiments. A last ditch battle results in the "darkest day of horror the world has ever known".