What happened is Gull explained his beliefs and purpose(and that Netley already belongs to him and has to do as he says). Unfortunately, due to the rules, I only included some highlights--one really has to read the whole chapter to understand what's so horrifying at the end.
But this is where he gives every reason you could want to know why he, as a Mason, later kills the women. The scariest part is that Gull's not yet really crazy here.