In one of the castles, a woman's character sprite was rendered incorrectly. Characters that are not inside rooms before you enter are supposed to disappear when you do go inside. This simulates you being inside the room by making the screen completely vanish on the outside and leaving the room and what's inside as the only thing visible. Here they got it backward; the woman was accidentally made visible only when you're inside a room. And since she isn't in or near a room in the game, she thus becomes the Amazing Invisible Woman. If you can find her invisible version, then you can talk with her.
Submitted by: fz2001us