The main plot device of the book (this is not a spoiler) is that people can have their memories erased through "binding". A character uses this to their advantage and manipulates others who have had their memories removed and know it, but can't remember what they had removed.
Neither of the two main characters are assaulted. There are references to several female maids who have been sexually assaulted in the past, but it doesn't happen explicitly in the text.