"Every exit is an entrance someplace else." -- Tom Stoppard
Despite some naysayers, ABC's Lost is still one of the most popular shows on television. Some viewers have gotten frustrated with its complicated and at times confusing plot developments, but I consider its nonlinear story structure to be one of its more compelling features.
Every movie and television show, every book and comic, tells a story. A plot can be defined as how that story is revealed. Typically stories have an obvious beginning, middle, and end. Traditional story arcs have multi-act formats, with tried-and-true beats, establishing scenes that lay out the conflict, climaxes, and resolutions.
Lost tells its tale backwards and forwards, playing with everyone's preconceptions of space and time. Lost didn't invent nonlinear plot-telling, but it certainly is using it well.
Others have set the standard for plots that don't progress in the usual way. Some notable ones that come to mind are Citizen Kane, the Star Wars saga, Pulp Fiction, and Memento.
In Citizen Kane, Charles Foster Kane's story is revealed as we try to find out the meaning of "rosebud." The entire Star Wars storyline changes when we learn the secret of Luke Skywalker's parentage in The Empire Strikes Back, which wouldn't have had the impact it did if we'd learned that plotpoint earlier by seeing the prequel chapters first. Pulp Fiction's plotting works even though the chronology is scrambled. Memento reveals its secrets to both its lead character and its audience by showing its scenes in reverse order.
In Lost, we are introduced to characters and then discover their backstories which flesh them out more and give rich, new meaning to previous actions. The time travel plot makes the jumps more than just a gimmick. It also makes us take notice of the greater themes that the writers are attempting to explore: destiny, memory, fate, redemption, the often blurred line between reality and the dreamworld, faith, and in the case of Hurley, sanity (or the questionable lack thereof).
As I wrote in Paul Levinson's excellent blog Infinite Regress, it would be brilliant if the producers released a "linear" edit of Lost when the series is complete, so all the flashbacks, flashforwards, time travel plotlines could be seen as they occurred historically, in chronological order, revealing how everything fit together and was planned all along.
Of course, that might also reveal plotholes or unanswered questions. Time travel tales risk imploding into a vortex of paradoxes. So far, Lost has managed to stay true to the notion that whatever happened has happened and can't be changed. If so, and if the writers manage to answer all the questions that have been raised and continue to be raised, without making continuity errors, then Lost will be a benchmark of television history, not just for its ratings success, but also for its achievement in superb nonlinear narration.