Season 5, Episode 14:
The Variable
In flashbacks, Eloise discourages Daniel's childhood interest in playing the piano, telling him his destiny is to become a scientist. When he graduates, she rudely dismisses his girlfriend, Theresa, and tells him he has no time for distractions. She gifts him the notebook in which he will write his research. After Theresa's accident, Widmore visits Daniel to recruit him for the freighter mission, saying that the Island will heal his memory problems. Daniel is hesitant, but Eloise convinces him to go.
In 2007, Desmond is rushed to hospital after being shot by Ben. Eloise visits Penny at the hospital to apologize for Daniel causing Desmond's shooting. Much to everyone's relief, Desmond recovers. She meets Widmore, and slaps him when he reminds her that Daniel is his son too.
In 1977, Daniel tells Pierre that he is from the future, that Miles is his son, and that there is about to be a catastrophic energy leak at the Swan site. Daniel tells the young Charlotte that she has to leave the Island. Kate agrees to bring Jack and Daniel to the Others to find Eloise. They have a shootout with Radzinsky when gathering weapons. Radzinsky discovers that Sawyer has Phil locked in his closet. Daniel explains that he plans to detonate the Jughead bomb to destroy the electromagnetic energy at the Swan, so that the Hatch will never be built and Oceanic 815 will never crash on the Island. He walks in the Others' camp, and holds Richard at gunpoint, demanding to speak to Eloise. Eloise shoots him in the back, and Daniel realizes that she has known this would happen his entire life, telling her that he is her son just before he dies.
Tropes in this episode include:
- Call-Back: Daniel telling young Charlotte to leave the Island happens exactly the way adult Charlotte described the event just before she died in "This Place Is Death".Young Charlotte: I'm not allowed to have chocolate before dinner.
Faraday: It's okay, sweetheart. I won't tell. - Cross-Referenced Titles: With Season 4's "The Constant". Both episodes prominently feature Daniel Faraday and his time travel theories.
- Death by Irony: Daniel is killed by his own mother while she's pregnant with him. It's played for horror, as while he's dying, Daniel clearly realizes the horrific irony that Eloise knew this would always happen.
- A Death in the Limelight: Daniel dies in his first centric episode.
- Five-Second Foreshadowing: In the same line in which Widmore reveals he is Daniel's father, he refers to Daniel in the past tense. Daniel's killed in 1977 in the next scene, something that Daniel realizes too late Eloise always knew would happen.
- Internal Reveal: Daniel tells Pierre Chang that Miles is his Kid from the Future but Dr. Chang doesn't believe him yet.
- Just Between You and Me: Widmore meets Daniel and tells him the truth that he faked the plane wreck, but notes that Daniel won't remember this conversation.
- Oh, Crap!: Daniel's face as he lies dying is full of shock and regret as he realizes that Eloise always knew he was destined to die on the Island and thus his plan to stop the plane crash is probably going to fail.
- Retroactive Precognition: Daniel's very detailed research on the DHARMA Initiative gives him the ability to predict events in 1977 almost to the minute, allowing him to arrange a meeting with Pierre at the Orchid and know exactly when "The Incident" at the Swan site will happen.
- Screw Destiny: Although Daniel has been steadfast in his belief that the past cannot be changed until this point, he now believes that this theory fails to account for human beings having free will, and plans to prevent the crash of Oceanic 815.Daniel: We think. We reason. We make choices. We have free will. We can change our destiny.
- Stable Time Loop: It's revealed that Daniel's entire life has been one of these, as his mother, having shot him when he travelled back in time to 1977, ruthlessly discourages him from anything that might distract him from the scientific career she knows he's destined for and pushes him along the path that will result in him being sent back in time in the first place.
- Unwitting Instigator of Doom: Daniel kickstarts his plan to detonate Jughead by walking into the Others' camp, holding Richard at gunpoint, and demanding to speak to Eloise. Such a hostile entrance naturally gets him shot in the back, and as he dies, he realizes that Eloise killed him and always knew she would. This not only locks Daniel's life into a Stable Time Loop that Eloise has to enforce at all costs, but when the survivors attempt to finish his plan to detonate Jughead without them, they end up causing the Incident, leading to the plane crash Daniel was trying to prevent in the first place.
- Wham Line: A case where the line contains two bombshells in one:Eloise: Don't talk to me about sacrifice, Charles. I had to send my son to the island, knowing full well that...Widmore: He was my son too, Eloise.
