Robert Neville, a doctor, due to an experimental vaccine, is the only survivor of an apocalyptic war waged with biological weapons. The plague caused by the war has killed everyone else except for a few hundred deformed, nocturnal people calling themselves "The Family". The plague has caused them to become sensitive to light, as well as homicidally psychotic.
Dr Robert Neville has developed an experimental vaccine which makes him the only immune survivor of a biological catastrophe. A gang of homicidal mutants blame science for their condition and attempt to kill him.