Lost: 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 its inhabitants of a catastrophe involving the Dharma Initiative research station, The Swan. Jack (Matthew Fox), Kate (Evangeline Lilly) and Daniel begin a gun 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.