The US Army has discovered a microscopic alien form in order to resurrect dead soldiers on the battlefield. After the experiment goes badly wrong, scientist Darren Hall steals the last specimen and hides out in a residential building hoping to reverse the damage. But the alien life form is accidentally set loose turning the building's residents into the walking dead. Hall and a small group of survivors must find a way to destroy the alien possessed and stop the virus spreading or its the end of the human race as we know it.