When a mutating, highly contagious fungus escapes a sealed facility, two employees – joined by a grizzled bioterror operative – must survive the wildest night shift ever to save humanity from extinction.

Twenty-eight days after a killer virus was accidentally unleashed from a British research facility, a small group of London survivors are caught in a desperate struggle to protect themselves from the infected. Carried by animals and humans, the virus turns those it infects into homicidal maniacs -- and it's absolutely impossible to contain.