Lost is about the survivors of Oceanic flight 815, but only two of them actually appear in the show’s greatest episode. Lost season 4, episode 5, “The Constant,” delves into time travel and its consequences when present-day Desmond Hume (Henry Ian Cusick) suddenly starts flashing back to his younger self in 1996. His mind flicking between the past and 2004, Desmond must figure out how to anchor himself in the correct timeline before becoming another victim of the notoriously turbulent Lost cast.

“The Constant” received critical acclaim and was nominated for numerous awards, including Emmy nominations for its cinematography and musical score. “The Constant” was also selected as the episode representing Lost season 4’s Emmy nomination for Outstanding Drama Series. 16 years later, the Desmond-led episode is still widely considered to be Lost‘s best episode, even when compared to other stellar installments such as the captivating pilot and season 3’s game-changing finale with Charlie’s death.

“The Constant” Is Missing All Original Plane Crash Survivors Except Jack & Sayid

Desmond Takes Center-Stage

Sayid Jarrah (Naveen Andrews) travels with Desmond to investigate season 4’s newly-arrived freighter and determine whether its crew can be trusted. As far as Desmond is aware, Sayid is the only person on the freighter who knows and trusts him. They make contact with Jack Shephard (Matthew Fox), who is still on the island, via satellite phone, but other than Jack and Sayid, no other Oceanic Flight 815 Lost survivors appear in the episode.

Desmond, Penny Widmore (Sonya Walger), and Daniel Faraday (Jeremy Davies) all appear in both the 1996 and 2004 timelines. Nevertheless, “The Constant” belongs to Desmond and his love story with Penny that transcends time, as she becomes his “constant” in the past and present, grounding Desmond in 2004 and bringing his damaging flashbacks to a halt. Lost is known for being an ensemble series, but that doesn’t negate how impressive it is that “The Constant” is able to tell such a compelling story with almost none of the show’s original cast members.

Why Lost’s “The Constant” Is Still One Of The Greatest TV Episodes Of All Time

“The Constant” Endures As A Standalone Story And A Pivotal Turning Point In Lost

On its own, “The Constant” is a moving love story about Desmond and Penny, with their bond proving strong enough to save Desmond from the perils of time travel. Seeing Desmond make contact with Penny, his constant, in the present day for the first time in three years is a rewarding payoff both within this individual episode and for those following Desmond and Penny’s relationship across the entire series. In the context of Lost‘s labyrinthine overarching story, “The Constant” is important because it is Desmond’s phone call that allows Penny to finally locate the island.

This ultimately enables Penny to save Desmond, Frank Lapidus (Jeff Fahey), and the Oceanic Six at the end of season 4. “The Constant” also establishes many of Lost‘s time travel rules – an important foundation to lay, given how integral time travel becomes for all characters in season 5. It is remarkable that Lost‘s best episode, and one of the best episodes in the history of television, revolves entirely around a character introduced in season 2, and that the only two original characters present have limited roles.