20 Things You Somehow Missed In The Prestige
4. Rebecca Hall's Guilt
The female characters in The Prestige, Sarah Borden and Olivia Wenscombe, suffer greatly during the film as they are caught between the two warring magicians whom they look upon as their lovers and, in Sarah's case, both a husband and a father.
At first, the lives of Borden and Sarah seem charmed, however it becomes evident that their life based on his success as a magician is far from ideal. Growing increasingly disturbed by her husband's activities, a distressed Sarah one day tells Borden: "I know what you really are".
This line was not in the script and Rebecca Hall later revealed that she felt terrible as soon as she had said it, as it risked exposing a major plot point. However, Christopher Nolan liked the line so much that he kept it in the finished film, perhaps believing that, as Borden is supposed to be having an affair with Olivia by this point in the plot, audiences would simply think that Sarah had learned the truth and wanted retribution.