18 Years Later, The Best TV Episode Of All Time Still Keeps Me Awake At Night

It’s been almost two decades since the best episode of TV reshaped the entire medium on ABC, and it’s still one that keeps fans up at night thinking about its ingenious story. There are certain TV shows that permanently alter the history of the medium, for better or worse. Without the success of the long-running cartoon comedy The Simpsons, it is unlikely that the adult animation boom of the 1990s and 2000s would have ever happened, meaning viewers would never have gotten shows like Futurama, South Park, Family Guy, and King of the Hill.

The knock-on implication of this is that, without those shows making adult animation a thriving genre by the 2010s, viewers would never have gotten Big Mouth, Rick and Morty, BoJack Horseman, and dozens of other hits from this more recent era of R-rated cartoons. In the same vein, the success of the small-town mystery/psychological horror mashup Twin Peaks begat The X-Files, and that Fox show’s blend of police procedural plotting and paranormal twists indirectly led to Buffy the Vampire Slayer, Angel, Supernatural, Fringe, Grimm, Lucifer, Evil, and many, many similar shows.

When it comes to looking back on the best episodes of TV in the last thirty years, there is another title that looms large over the medium’s evolving history. Lost was a hit ABC series that debuted in 2004, and its blend of mystery, sci-fi, fantasy, and character-based drama would go on to help define the landscape of TV and streaming throughout the 2000s, the 2010s, and the 2020s alike. One of the definitive mystery-box shows, Lost inspired everything from Stranger Things and Severance to From, Yellowjackets, The Leftovers, and Apple TV’s masterpiece Pluribus.

We Still Think About How Good Lost's "The Constant" Is

18 years later, the best episode of Lost remains a testament to the power of the show’s innovative storytelling style. While it would be a fool’s errand to try and unspool the entire elaborate plot of Lost in one article, suffice to say, the show focused on a group of survivors of an airplane crash who find themselves abandoned on a mysterious island where time and space don’t work the way they usually do.

While this might be an oversimplification, it’s enough of a synopsis to explain Lost season 4, episode 5, “The Constant.” This outing opens with two of the island’s inhabitants, Sayid and Desmond, trying to travel from the island to a nearby freighter. As they do, Desmond’s mind jumps back to 1996, during his time in the British Army, before leaping back to 2004, where he awakes with no memory of anything that happened after 1996.

When the pair arrive at the freighter, they learn that guest star Fisher Stevens’ George Minkowski is suffering the same fate, becoming “unstuck in time” like Desmond. As the plot of “The Constant” unfolds, the freighter’s resident physicist, Daniel, faces a race against time as he tries to get Desmond to contact his younger self in 1996 to come up with a solution to this time loop. Desmond ends up using his former love interest Penny as a "constant" that allows him to anchor his consciousness in both 1996 and 2004, preserving his sanity and his brain’s integrity.

We Still Think About How The Episode's Time Travel Fits Together

While the term “unstuck in time” is borrowed from author Kurt Vonnegut’s seminal novel Slaughterhouse 5 and the episode’s inspiration more broadly came from an episode of Star Trek: The Next Generation, part of what made “The Constant” so astounding was its innovation. Like the blockbusters of Christopher Nolan and Dennis Villeneuve in the years that followed, the show trusted viewers to follow a complicated, dense time travel story without oversimplification or excessive explanation.

There was plenty of time travel on TV before, but “The Constant” took the concept as seriously as Shane Carruth’s acclaimed indie movie Primer while still remaining accessible to a mainstream audience. In the years that followed, sci-fi TV shows would take advantage of the level of cerebral sci-fi that Lost made mainstream. It is no exaggeration to say that shows like The Expanse and Foundation, not to mention Westworld, Dark, Devs, and Severance, would likely never have been green lit without “The Constant.”

We Still Think About How "The Constant" Links To Lost's Wider Mythology

While “The Constant” played a pivotal part in TV history, this shouldn’t overshadow the unique role that the episode played in Lost’s in-universe story. The episode’s story of Desmond trying to find his way back to the love of his life is so emotionally wrenching that it can be tough to remember just how much lore “The Constant” revealed when it first aired, and how many fan theories the episode confirmed and debunked in the process.

The plot of “The Constant” was one of the first pieces of concrete evidence that the island was a temporal anomaly whose surrounding energy pockets allowed individuals to become unstuck in time there. Not only did the eponymous constant offer characters a theoretical way to survive the temporal unmooring caused by the island, but the episode also proved that Desmond, at least, could withstand becoming “unstuck” without dying or losing his mind.

We Still Think About How "The Constant" Came During Lost's Most Difficult Period

Although a lot of promising shows like Heroes were themselves unmoored by the 2007/2008 Writers Guild of America strikes, this was not the only factor that ensured “The Constant” arrived at a complicated time for Lost. Not only was season 4 trimmed from 16 episodes to only 13, but long mid-season gaps increased hype around a show that had already faced criticism for failing to give answers to its many lingering mysteries.

The earliest seasons of Lost were almost universally praised for setting up an immersive, ambiguous mystery, but the longer the show went on, the more viewers started to demand answers. By finally leaning into hard sci-fi instead of unclear paranormal phenomena with little in the way of explanation, “The Constant” proved that Lost could deliver more than just empty promises.

Debate rages on about whether or not Lost lived up to its potential with the show’s divisive series finale. However, in an era when sci-fi TV is more ambitious than ever thanks in large part to Lost’s ability to convince mainstream audiences to follow its unapologetically complex, dense story, the show’s best episode ever proves that the series had a massive impact on the medium.