They arrive in silence, out of dark skies. They infest human hosts and consume them. And they are everywhere. They are Parasites: alien creatures who must invade and take control of human hosts to survive. Once they have infected their victims, they can twist the host's body into any abominable shape they choose: craniums splitting to reveal mouths of sharp teeth, batlike wings erupting from backs, blades tearing through soft hands. But most have chosen to conceal their lethal purposes behind ordinary human faces. So no one knows their secret, except an ordinary high school student. Shin managed to arrest the infestation of his body by an alien parasite, but can he find a way to warn humanity of the horrors to come?