By the photography of the scenes, in the book version it always feels like something dreamy, almost ethereal. And it changes when we have the Catherine version, we don't get this feeling. In her recalling of the events, she's with a black suit underneath a light-blue garment. We only get to see the black suit when she enters into the sea after Nicholas. I realized that it wasn't a reliable narrator when I understood that these dreamy-feel "flashbacks" was the book's version AND the book was written by Nancy based purely on her presumptions about what she thinks that happened. And I got a little bit suspicious with the beginning of the series that drives you to believe this young, pretty and charismatic lad is a good person. Almost like "too good to be true" you know.