By failing to explore Libby’s backstory, Lost never cleared up a season 2 mystery. Played by Cynthia Watros, Libby was a major season 2 character and Hurley’s love interest. Alongside Ana Lucia, she was killed off unexpectedly as a result of Michael’s betrayal and his efforts to save Walt.
At the time, Libby’s death in particular caught viewers by surprise – and not because it had happened at the hands of a once-trusted main character. Prior to her demise, there was a sense that Lost still had a lot left to do with her character. Unlike the other tail section survivors who had joined the group – Ana Lucia, Bernard, and Mr. Eko – Libby had yet to receive her own flashback episode. And there was certainly an expectation that she would get one eventually. After all, Lost season 2’s “Dave”, which explored the period Hurley spent at a mental institution, dropped a big reveal about her past. The ending of the episode revealed that Libby, who had no obvious mental health issues, was secretly a patient at the same time as Jorge Garica’s Hurley.
After her death, Libby returned in the Lost two-part season 2 finale as a character in Desmond’s flashbacks, but the show never explained what she was doing in the mental institution. The way the scene was framed had given a strong impression that it would be important later but it never was. Since then, Lost creators Damon Lindelof and Carlton Cuse have shed on why it wasn’t discussed and the reason for her being there. Apparently, Libby’s situation was tied to the impact that her husband’s death had on her. Lost didn’t get a chance to dive into this because Watros chose not to remain on the show [via Digital Spy].
Instead of exploring it more deeply, Lost alluded to the reason during her talk with Henry Ian Cusick’s Desmond, where she mentioned that her husband had died. The show itself never directly tied this tragedy to Libby’s history as a mental patient, but Cuse has confirmed the connection. He also said that Watros’ decision to leave the show is what caused them to scrap their plans for Libby’s backstory. According to Cuse, Lost was committed to telling the stories of characters who were still on the show. This didn’t include people who had already died. He said that bringing Libby back in another character’s story to answer these questions about her past would be “insulting”.
In other words, her death made an explanation for the Libby mystery unnecessary and a bad fit for the stories that followed. Lost’s big reveal about her link to Hurley was made irrelevant only a few episodes later. Interestingly, the series revisited this aspect of her character in season 6 by having her in the same mental hospital in the show’s flash-sideways story, where her presence was explained by her memories of her life on the island. But in keeping with the show’s approach to Libby’s backstory, the reason why she was there in the real world was ignored completely.
