A ghost is an apparently supernatural image of someone or something that is thought to be deceased or no longer in existence. According to traditional belief, when a person dies, their soul exits their body and makes its way to the underworld or Hades (in Greek mythology according to Classics scholar Elizabeth Vandiver); in Christian theology as well, the soul is believed to depart the body and either go to heaven or hell. In this context, a ghost is a soul that, for reasons unknown, remains among the living, haunting people, sometimes scaring them or otherwise trying to cause fear. Images of ghosts in modern times often have a fog-like character, not fully solid yet not fully invisible, as if a person can see through them.