The occurrence of a “plague” differs from that of common diseases. Common illnesses can often be cured with  a doctor’s skilful treatment and the right medicine. If an individual’s illness is not contagious, it generally has no impact on others. However, when a plague strikes, it is as if a vast expanse of the sky is devoured and shrouded by a venomous demon. As the poisonous miasma fills the air, everyone is seized with panic and begins to fear for their own safety.