Let's be honest. If you haven't already consumed all 103 hours of ABC's "Lost" — every time-travel twist, every return from the dead, every delicious WTF moment — you're pretty much screwed when it comes to the premiere of the show's final season Tuesday night (February 2). Actually, even if you have devoured each episode multiple times, you're still going to have to do some hard-core studying to prepare yourself for the beginning of the end.

That's where MTV News' "Lost" cheat sheet comes in, hitting the big points and the crazy twists you'll want to keep in mind when the Island madness begins at 9 p.m. ET.

Season Five in a Flash
Many of our time-traveling heroes — Jack (Matthew Fox), Kate (Evangeline Lilly), Hurley (Jorge Garcia) and more — spent a chunk of last season stuck in 1977, toiling as members of the DHARMA Initiative on their mysterious Island home. Then some of them got the bright idea to detonate a hydrogen bomb over a pocket of electromagnetic energy in the hopes that the explosion would essentially reset the space-time continuum so none of them crash on the Island in the first place.

The last thing we saw in the finale was a white screen after the bomb went off. So what happened? Did the Losties die, as some in present Island time suggested? Or did the plan work, ensuring that Oceanic Airways Flight 815 landed safely in Los Angeles and essentially negating the events that have occurred since episode one? Expect answers to these central questions by the end of the season premiere.

John Locke and the Man in Black
For a while last season, we thought John Locke (Terry O'Quinn) had been resurrected from the dead to serve some greater purpose on the Island. In the season-five finale, though, we learned his likeness had actually been taken over by the über-mysterious Man in Black. Who is this MIB, and what is his role in the Island's mythology? Does he have any connection, as many have speculated, to the Smoke Monster, that ominous beast often referred to as the Island's security system? What's the MIB's plan? Is he good or bad, and can we even make such pat distinctions at this point?

Where (and When) Is Everyone?!
After all these plot twists, turns and backflips, it's hard to keep straight just where and when every "Lost" character is at this point. Here's what we know: In present Island time, Benjamin Linus (Michael Emerson) killed Jacob, the mystical dweller who's played a role in so many of the castaways' lives. Locke, we learned, was not Locke but actually the Man in Black. This was a fact ageless Richard Alpert (Nestor Campbell) also figured out at the finale's end. Also in present time, Sun (Yunjin Kim) was still searching for a way to rescue her hubby, Jin (Daniel Dae Kim).

Back in '77, Jin, Jack, Kate, Hurley, Sawyer (Josh Holloway), Miles (Ken Leung) and a grievously injured Sayeed (Naveen Andrews) were last seen moments before the nuke exploded. Rose (L. Scott Caldwell) and Bernard (Sam Anderson) were also in that time, living peacefully in their makeshift beachside retirement village. Last time we checked in with Desmond (Henry Ian Cusick), he was recovering in an off-Island hospital after a nasty run-in with Ben. Then there's Claire (Emilie de Ravin), who hasn't been seen since season four, when she was kicking back in an Island cabin, possibly alive and possibly not. In fact, don't even get us started with all the dead characters we haven't seen in forever — from Boone (Ian Somerhalder) and Shannon (Maggie Grace) to Charlie (Dominic Monaghan). Expect to see at least some of them return, but in what form we can only guess.

So, that's where everyone once was (or wasn't) at last season's end. Goodness knows where we'll find 'em at this season's start.

Questions, Questions, Everywhere
Above we've touched on some of the key questions on our minds heading into season six. But it wouldn't be "Lost" if we didn't have a crapload of other queries swimming in our noggins — 108 queries, to be exact. Study up and see how many are answered in the coming months: How is the Island able to heal wounds and ailments? Why can't women give birth on the Island? What are the whispers? And so on.

OK, Go
We've been following this show religiously since its premiere in 2004. Now we're 18 episodes away from its completion. And we're pumped (follow our live blog of the two-hour premiere at MTV Movies Blog). Will we be satisfied on Tuesday night? Will we be satisfied after the series finale?

"We are committed to the notion that we are going to give the audience a fair ending," exec producer Carlton Cuse told MTV News. "Not a sort of 'pull the rug out from under them' ending."