Question:
In some ways the wall itself was responsible for subsequent overcrowding and disease because people were too frightened to live outside it.

Does it follow that "People refused to live within the walls."?
Answer:
no

Question:
Nora now sits in an ominous stillness.

Does it follow that "Nora is moving a lot"?
Answer:
no

Question:
Just west of CityHall is one of Dublin's most important historic sites, Dublin Castle.

Does it follow that "Dublin Castle is situated to the east of CityHall. "?
Answer:
no

Question:
And, anyway, I'm not at all sure that it isn't actionable blackmail, you know."

Does it follow that "That might be actionable blackmail because of the phrases used."?
Answer:
it is not possible to tell