Overview
"The Constant" is the fifth episode of the fourth season of the American Broadcasting Company's (ABC) serial drama television series Lost, and the 77th episode overall. It was broadcast on February 28, 2008, on ABC in the United States and on CTV in Canada. It was written by executive producer Carlton Cuse and co-creator/executive producer Damon Lindelof and directed by executive producer Jack Bender. "The Constant" was watched by 15 million American viewers and is widely regarded as Lost's best episode and one of the best episodes of television produced in the 21st century. It was nominated for three Primetime Emmy Awards, a Directors Guild of America Award, and a Hugo Award.
In the episode, Desmond Hume (played by Henry Ian Cusick) and Sayid Jarrah (Naveen Andrews) are being flown by Frank Lapidus (Jeff Fahey) to the freighter where Lapidus' mission is set. After going through turbulence, Desmond's consciousness unexpectedly travels through time between 1996 and 2004. The helicopter reaches the freighter and Sayid and Desmond are introduced to communications officer George Minkowski (Fisher Stevens), who is "unstuck in time" like Desmond. The writers took twice the time expected to develop the episode's script; the biggest concern was the avoidance of a temporal paradox when dealing with time travel.
Plot
Desmond, Sayid and Lapidus experience turbulence while flying the 80 miles (about 130 kilometers) distance from the island where they were stranded to Lapidus' team's freighter, the Kahana. Desmond's consciousness travels back eight years to 1996, when he is serving with the British Army's Royal Scots Regiment. Moments later, when his consciousness returns to the present day, he neither knows where he is nor recognizes his companions, and has no memory of his life since 1996. After the helicopter lands, Desmond continues to jump between 1996 and 2004. He is taken to the sick bay, where a man named Minkowski is strapped to a bed because he is experiencing similar problems. Minkowski explains that someone sabotaged the radio room two days earlier and that Desmond's ex-girlfriend Penny Widmore (Sonya Walger) has been trying to contact the freighter. Sayid uses the satellite phone to contact Jack Shephard (Matthew Fox) on the island and explains that Desmond appears to have amnesia. Daniel Faraday (Jeremy Davies), a physicist from the freighter, asks Jack whether Desmond has recently been exposed to a high level of radiation or electromagnetism.
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