*WARNING* this post contains spoilers.
So, if you're still reading this it means you've probably finished the season. If so, you'll know it ends with Joe Goldberg's (Penn Badgley) ex Candace returning to the scene, even though most assumed she was dead.
However, it's completely different to the book's ending!
Speaking to The Hollywood Reporter about the changed ending, Sera Gamble said the decision was all about adding an unexpected twist.
"We knew we were going to start flashing back to Candace, as Caroline does in the book," she explained, saying that the show misled viewers deliberately into thinking Joe had killed his ex-girlfriend.
Sera continued, "We just wanted to do something more surprising and [we also realised] that she was such a substantial and interesting character."
She even believed that the book would end differently when she read it.
"[There] was plenty of material to work with, but also there’s something a little scary and crazy about knowing that that’s the ending of your season," she added.
"There were so many times when we were trying to bargain with ourselves and see if there was another way through".