The Variable

"The Variable" is the 14th television episode of the fifth season of Lost, and the 100th episode overall. It originally aired on the American Broadcasting Company (ABC) in the United States on April 29, 2009. The hundredth episode milestone was celebrated by cast and crew on location in Hawaii. In the episode, Daniel Faraday (Jeremy Davies) returns to the Island in order to warn the inhabitants of a catastrophe involving the DHARMA Initiative research station the Swan. Jack (Matthew Fox), Kate (Evangeline Lilly) and Daniel begin a fight with DHARMA, leading DHARMA to go after Sawyer (Josh Holloway) and Juliet (Elizabeth Mitchell). In flashbacks, Daniel's relationship with his parents, Eloise Hawking (Fionnula Flanagan) and Charles Widmore (Alan Dale), is shown.

The episode was written by executive producers Edward Kitsis and Adam Horowitz and directed by Paul Edwards. It serves as a companion piece to the season four episode "The Constant", another episode that heavily features the character Daniel, and the third Lost episode to deal directly with the concept of time travel. Since airing, the episode has received generally positive reviews from television critics, mostly complimenting Davies's performance.

At a young age, Eloise asks Daniel if he knows what destiny is and then tells him that he has a special gift — his brilliant mind — and that his destiny relies on this. After Daniel graduates from Oxford University, Eloise gives him a new journal as a gift and again reminds him of his destiny. Meanwhile, Daniel has received an enormous research grant from Charles. Years later, following the crash of Flight 815, Daniel has suffered severe psychological effects from performing experiments on himself; he has lost his mental acuity, and now lives with a caretaker. While watching the news coverage of the discovery of the Flight 815 wreckage in the Sunda Trench, Daniel is visited by Charles, who tells him that he faked the found wreckage and that the real plane actually landed on the island. Charles invites Daniel to go to the island, which Charles claims will cure his psychological problems. Eloise later visits Daniel and further encourages him to go to the island.

Following the events of the previous episode, "Some Like It Hoth", Daniel has returned to the island, having spent three years in Ann Arbor, Michigan, conducting research for the Dharma Initiative. He has returned because Jack, Kate and Hurley (Jorge Garcia) have managed to travel back in time and become part of the Initiative. After learning from Jack that they were sent to the island by Daniel's mother, Eloise (younger: Alice Evans; older: Fionnula Flanagan), Daniel visits Dr. Pierre Chang (François Chau) at the Orchid station (as seen in "Because You Left") and warns him of a catastrophic event that is to occur at the Swan station in six hours. Dr. Chang does not believe Daniel when he says that he is from the future, and Miles (Ken Leung) does not confirm Dan's story, even after Daniel informs Dr. Chang that Miles is his son from the future.

At the Barracks, Sawyer, Juliet, Jin (Daniel Dae Kim), Hurley and Miles decide that they will flee to the survivors' original beach, abandoning Dharma. But Kate, Jack and Daniel decide to visit the island's native population, the "Others", and get help to prevent the impending disaster. They arouse suspicion from Dharma's head of research, Radzinsky (Eric Lange), while trying to steal weapons, and a gun fight ensues. The survivors are able to escape; however, Radzinsky brings his team to Sawyer and Juliet's house, where they find Dharma member Phil (Patrick Fischler) tied up. Meanwhile, Daniel explains to Jack and Kate that he intends to detonate the hydrogen bomb that had been buried on the island in 1954 in order to prevent the construction of the Swan, which in turn will ensure that Oceanic Flight 815 never crashes on the island, which means it never becomes visible to Widmore's team, so he never sends the freighter which brings himself and Charlotte, therefore Charlotte does not die. Daniel enters the Others' camp with his gun drawn and demands that Richard Alpert (Nestor Carbonell) take him to see Eloise; Eloise shoots Daniel in the back as they argue, to Richard's disapproval. As he dies, Daniel tells Eloise that he is her son, and comments that she (referring to her older self) knew he was going to die on the island and sent him anyway.

Following the events of "Dead is Dead", Desmond (Henry Ian Cusick) is brought to a hospital, having been shot by Ben (Michael Emerson). While waiting, his wife Penny (Sonya Walger) is visited by Eloise, who apologizes for involving Desmond in everything that has happened. Penny later visits Desmond, who is expected to make a full recovery. Charles, who is also Daniel's father, speaks with Eloise outside the hospital, but does not visit his daughter.

"The Variable" was written by Edward Kitsis and Adam Horowitz and directed by Paul Edwards. Like most season five episodes, it features elements of time travel. It serves as a companion piece to the season four episode "The Constant", another episode that heavily features the character Daniel, and the third Lost episode to deal directly with the concept of time travel after "Flashes Before Your Eyes" from the third season and "The Constant" from the fourth season. In "The Constant", Desmond and Sayid (Naveen Andrews) are on their way off the island when their helicopter hits turbulence, causing Desmond's 1996 consciousness to take over his 2004 body and switch uncontrollably between 1996 and 2004. Lost show runner Damon Lindelof said the fifth season of the show has "flung major characters across decades, leaving them — and the audience — feverishly attempting to keep events straight and the end game in sight." In "The Variable", the viewers would get a few more pieces of the puzzle, Lindelof said, and added: "We're not promising any big whiz-bang flash pyrotechnics, but it does serve as a companion piece to another memorable episode, last season's 'The Constant', in which Desmond endured vicious, turbulence-caused side effects from traveling in time." Lindelof also commented that the fifth season is about the rules of time travel as explained by Daniel, and said, "We've never done a flashback story for Daniel, so he's very mysterious. Some of those mysteries will be answered in this episode." Since Lindelof and his show runner partner Carlton Cuse wrote "The Constant", they thought the "sister episode" should be written by someone other than them, which led to Kitsis and Horowitz writing it. The two show runners were pleased with the outcome of the episode. Cuse thought it was one of the best episodes of the season.

The episode features the death of Jeremy Davies' character Daniel Faraday. Daniel was introduced in the fourth season and was originally intended to be a minor character only. However, his quiet demeanor and seemingly good heart made him a favorite with the fans, so Lindelof and Cuse decided to expand Daniel's role, which has led to him being a key player in Lost's eventual resolution. In response to Daniel's death, Cuse said, "It was an incredibly painful thing to kill this beloved character, but we feel that’s what this show has to do. His death is kind of the culminating event in the entire season. It really ends one chapter and commences the start of the final chapter of the entire series." Once the show runners explained that to Davies, he was saddened that his full-time status on Lost was coming to an end, but put the story "above his own personal self". Damon seconded Carlton's emotions, adding that Jeremy took the news well: "When Carlton and I called Jeremy to explain what was going to be happening with Daniel, we’ve never had a more awesome exit interview with somebody on the show. For us, Daniel really was the cornerstone of the fifth season – he really shined. I can’t imagine what Season 5 would have looked like without Jeremy Davies. When you think about all the crazy stuff that had to come out of that guy’s mouth, for him to be as interesting and emotional and poetic as he was is really extraordinary." The cast of the show said Davies would be missed, though he may not be done with Lost — Carlton commented that Jeremy's "full-time" status was over, but dead characters have been known to reappear on the show. Michael Emerson, who plays Ben, said Davies was "a great sensitive guy who got deep into his character, he really lived it."