The idea of the dead visiting dreams is a common tale among the folk, but many hold the belief that what you believe exists, and what you do not, does not. Even when burning joss paper for relatives, it's done for the peace of mind.
Are ghosts real? Who can say for sure?
Even Khaza Zuck couldn't clarify, although he exorcized spirits, and even though he was an extraordinary person, this was merely a technique inherited from his ancestors.
Yusuf Zuck asked him why Ariel Higgins had come to him in dreams twice in a row, but he couldn't answer—because it was impossible to tell. If he told Yusuf Zuck that Ariel Higgins had become a ghost, then where was she?
If he said she had not become a ghost, but what if she really had become one? What then?
This matter really was one of belief making something exist or not.