I’m curious about how Henry has come to believe. Other than the fact that he is a gullible child – lol!
What steps were taken to cause Mary Margaret to give Henry the book. And where did Mary Margaret get the book in the first place? I would suspect someone (August or Mr. Gold) convinced Mary Margaret to give Henry the book. If not August or Gold, then someone who received a suggestion by August or Gold (possibly Archie as a part of Henry’s therapy sessions).