 One pivotal role in the series is that covered by the Medusa virus, a mortal disease so named after the Medusa from Greek Mythology, the Gorgon whose eyesight could turn anyone and anything into stone at a mere glance.The virus itself is extremely virulent, infecting its victims' cells and causing seizures while drying up the body, turning the infected into a solid, stone-like corpse.While perceived as a terrible malady by the world, in reality the Medusa virus is not a virus at all, being a shapeless presence brought to Earth from outer space.