Speaking about the book-to-TV changes, writer Jenna Lamia told IndieWire that one reason for the change was that, unlike the book, you’re not “privy to a lot of Merritt’s thoughts,” and having a lot of voiceovers “wasn’t going to work.” So, Jenna felt it would be more “satisfying” for TV viewers to have a murderer “who fully intended to murder the person they murdered.”

She continued, saying, “So for the show, and Elin was totally supportive of this, we decided that the killer had intended to kill the person she kills and that she had a very clear motive for doing so, and it wasn’t just jealousy. So [we] added the money plot. It needed to be a little more crisp.”