A viral disease that paralyzes and hardens the limbs, eventually solidifying the entire body into a stone-like state, causing death. Current strains of the virus are not highly contagious, and can be cured with the injection of a vaccine. In recent years, several cases of disease brought on by a newer, mutated version of the virus have raised new concerns. In response, scholars in Astral have taken up the duty of researching and developing a new vaccine.