May 21, 2010 -- It's been a long haul for faithful "Lost" viewers, but the end has come.
For six years, we've cheered on a complicated batch of plane crash survivors as they battled polar bears, ageless island inhabitants, time travel, the smoke monster and one another.
We've watched Sawyer morph from a sarcastic egomaniac to a sarcastic unlikely hero with a hardened heart of gold. We've cheered on Hurley as he found his confidence. We cried when Jin and Sun were finally reunited only to drown in a crippled submarine.
And we've been endlessly teased with a twisting labyrinth of questions as the show wound itself around in circles of mythology, faith and science fiction.
To be fair, viewers have been given the healthiest dose of answers since the show began -- the origins of the Adam and Eve skeletons found in season one, the birth of the smoke monster and how Richard Alpert has remained so gorgeously ageless for centuries.
But there are still a smorgasbord of mysteries left. Will the "Lost" series finale (Sunday, May 23 at 9pm ET on ABC) be able to answer them all?
'Lost' Numbers: 4 8 15 16 23 42
It's become common theory in the blogosphere that the meaning of the series of numbers, central to so many of the island's events, may never be revealed.
The numbers -- used by Hurley to win the lottery and Desmond to keep the hatch from exploding -- have popped up dozens, perhaps hundreds, of times over the course of the show.
Producers have used them almost as a "Where's Waldo" type of challenge for devoted Losties, sticking them on sports jerseys, bedside alarm clocks. They've even served as the flight number for the doomed plane itself.
But do we really need to know their significance? Probably not.
Origins of Jacob and the Man in Black
Sure, we found out how they came to live on the island -- shocker, they're twins! -- when a recent episode revealed they had been born to a shipwrecked young mother and raised by an all-knowing woman who bashed the mother's head in shortly after she gave birth.
But when the young castaway questioned the island woman about where she came from, the woman simply brushed her off, saying, "Every question I answer will simply lead to another question."
It almost seemed to be a message from "Lost" producers, straight into the living rooms of the show's fans.
But where did Mother come from? And how was she infused with the power and responsibility to keep the island safe? It's a fate that now rests with Jack. But where did it all begin?
Smoke Monster Death: How to Guide
With a ferocious roar and streaks of lightning, the smoker monster -- now inhabiting John Locke's body -- has proved its ability to kill without much effort, flinging castaways, red shirts and other island dwellers into anything it can find.
But in the penultimate episode, Jack questions Smokey's nemesis Jacob on how exactly the pillar of smoke can be killed.
Yeah, we'd like to know that too.
Desmond and the White Light
We've all known Desmond Hume was special from the very moment he came face to face with the survivors back in season one. And not just for his mega-watt grin and swoon-worthy accent.
Once the hatch-keeper, whose sole reason for existence was to push a button every 108 minutes -- there are those numbers again -- can withstand enormous quantities of the island's electromagnetic power even after others have died from the same exposure.
Charles Widmore, you know, before he was casually blown away by Ben, said Desmond was his "last resort."
Last seen killing time on the island at the bottom of a well and orchestrating a reunion back in the flash-sideways mainland, it has yet to be seen how Desmond's power will figure into the final showdown.
Impeccable Grooming: See Sawyer, Jack, Sayid, Hurley, Jin
The perfectly scruffy facial hair -- or lack thereof -- on most of the male castaways' faces could be described as a plot hole.
After all, who wants to see well-scuplted male leads reduced to resembling Charles Manson for six years?
But c'mon -- for a show that has taken care to explain exactly how the survivors found everything from food to pregnancy tests on a deserted island, we have yet to see where they found their stash of razors and clippers.
Deep Sea Adventures
This season's opener introduced the flash sideways. Because, you know, after years of figuring out flashbacks and flash forwards, viewers needed a little shake-up.
But as we got to see glimpses of a world we don't yet understand, we were also treated to a very quick flash of the island in a flash-sideways world -- deep under the ocean with a Dharma-branded shark circling overhead.
Uh -- how did that get there? Will the the battle for good and evil end with a ceremonial sinking of the island?
Shoes Off Everyone, Who's Got Four Toes?
Losties first got their glimpse of the giant four-toed statue watching over the island at the end of season two.
The statue in modern times is severed at the ankle, but flashbacks to the early Jacob days have included views of the back of the full statue. It appears to be an Egyptian god, the most popular theory that it's Sobek, a Nile god with the head of a crocodile.
It was revealed at the end of season five that Jacob lived inside the statue, but it has yet to be revealed where it came from or why it watches over the island. And who has four toes anyway?
The Flash-Sideways World: Hello Detective Ford
Beginning with the final season, viewers have been treated to life in the main characters' alternate universe even as they continued their island adventures.
Kate is still dodging murder charges and professing her innocence, Claire is still pregnant and trying to give the baby up for adoption, and Sayid is still a lean, mean killing machine with a guilty conscience.
But there are stark differences between the flash sideways world and the lives the survivors led before Oceanic 815 crashed in 2004.
Jack has a son. Ben is a European history teacher. Hurley is a successful business owner with no trace of the mental illness that put him into a mental institution in the regular world. Sawyer is a detective for Pete's sake.
Some have suggested this will be the life they enjoy once the showdown on the island is resolved, possibly resetting years of their lives and putting their island experiences out of their minds, save for some deja-vu trips.
But Desmond seems to hold the key and has now appointed Hurley as his sidekick in forcing the memories of the rest to dig deep and realize they all once knew one another in a very different place.
The producers of the show have said viewers are supposed to be confused. Job well done.
Where Did They Go? The Walt and Vincent Edition
The show relied heavily on Walt -- Michael's young son who was being brought back to live with his father after years of estrangement. When they crashed on Oceanic 815, they crashed along with Vincent, Walt's loyal yellow Labrador retriever.
Walt was supposed to have been special, to be able to do things and see things the others couldn't, including teleporting while being held hostage by the Others. But then his father took him off the island, and we saw little of him after that.
Michael ended blowing up along with Widmore's freighter -- can we call being blown up pulling an Arzt? But Walt hasn't been seen since a brief meeting with John Lock in season five's "Life and Death of Jeremy Bentham."
Is he a chill high-school student who still holds on to his penchant for knife throwing?
And Vincent -- after being in the care of the now-deceased Shannon and then the now-crazy Claire, the plane's only canine survivor hasn't been seen since season four, save for a brief appearance in season five under the care of time-traveling Rose and Bernard.
So where is he? Did he get eaten?
Richard Alpert: Smokey's Toss Can't Be the End
Oh, Richard. Oh, sweet, loyal, conflicted Richard. Rendered ageless by Jacob back in the days after Black Rock shipwrecked, Richard has formed alliances and dazzled us all with his naturally grown guy-liner.
After sitting out for a few episodes this season, presumably jungle-hopping with Ben and Miles, Richard was unceremoniously flung into the woods by the smoke monster.
That can't be it. The guy who can't die cannot be offed by a uber-gladiator toss offscreeen.
Will Richard come back to save the day?