So I think we are finally getting somewhere, answer-wise at least not a lot answered but a few things.
This weeks episode was good! So please don't read if you haven't seen it yet and don't want to read any spoilers. :)
The episode starts off with Jack, in a suit, laying on his back, in a jungle! Is it another flashback? Did he return to the island? At first you aren't sure (there is one clue though). You hear yelling, someone calling for Help! The voice sounds familiar, then you hear someone yelling "Jack!". So you know it isn't a flashback, because no one knew his name before. Jack runs, comes to a cliff/waterfall and sees Hurley in a lagoon struggling. Jack dives off the cliff and pulls him to shallow water. He looks around, and sees Kate. They rush to her.
(As to the clue I mentioned, you can tell that it isn't a flashback as Jack's hair is longer.)
Then we jumped back 36 hours. Jack, Sun, Ben, Desmond are all with Ms hawking again. She tells a bit about what Dharma was doing. Desmond gets mad and tells her the message from Daniel, warns Jack not to listen to her and leaves, even thought Hawking told him the island is not done with him yet. She then tells Jack, Sun, and Ben to get on Ajira flight 316 to Guam. She believes this will be the flight that will take them back to the island.
Hawking takes Jack into an office and gives him a letter from Locke. It was his suicide note. She also tells Jack that in order to "recreate" Flight 815 as close as possible, that Locke is taking Christians place. So Jack needs to give Locke something of Christians. Jack rejoins Ben, Sun has left. Then Ben leaves telling Jack he has to see an old friend, some unfinished business to attend.
Jack pays a visit to Ray, his granddad. After some talking, Jack helps unpack his granddad's suitcase (he was running away from the nursing home his lives at) and finds his dad's (Christian's) shoes. So he asks for them. As Jack returns home, with the shoes, he hears someone in his place. It is Kate. She is on his bed, and very upset. He asks what's wrong and she asks him if he wants her to go back to the island with him. He says yes, but asks where Aaron is. Kate tells him if he wants to go back, he can never asks her again anything about Aaron. He agrees.
The next morning, Kate sees the shoes and makes a joke that if he is wearing those on the flight, he might want to reconsider and wear some hiking boots. He tells her when he when to Sydney for his dad, he didn't have any nice shoes. Jack didn't believe Christian was worth the trouble, so instead of buying him shoes to be buried in, he placed an old pair of his own white sneakers on him instead. Kate leaves Jack's place, tells him she'll meet him at the airport. Jack gets a call from Ben. He needs Jack to go to the butcher shop and pick up Locke and bring him to the airport. We see Ben at a phone booth on a pier, and he's been badly beaten up.
Jack goes to the butcher and puts his dad's shoes on Locke and gives him the unopened suicide note back. Then off to the airport. As Jack is talking to the person at the ticket counter, Kate walks bye. Then Sun comes up behind Jack. Next thing you know, Sayid is being led past as well. But he is with a woman. We see her flash a badge and realize Sayid is in handcuffs (taking Kate's place?).
Next we see someone reading a graphic novel/comic book in Spanish. It's Hurley! He somehow found out about the flight. An announcement is made for standby passengers to buy their tickets. Hurley gets upset and runs up saying he bought the 70-some empty seats. The attendant asks him why he would prevent the others from getting a flight. He looks around and just says "They can take the next flight". (He just doesn't want them to die in case this flight is "the one" to take them to the island again.)
So we get on the plane. There is Jack, Kate, Sun, Hurley, and yep! Sayid also. So 5 of the 6 is on the plane. Just before take-off, who comes running on board? Why Ben of course!
The 5 are nervous, after they get into the air Jack sits with Kate. You hear the pilot come on and announce his name. Well guess who?! Its none other than Frank Lapidus. So Jack asks to speak with him. The flight attendant tells Jack the found something of his. The note from Locke. So Frank comes out, and he notices one by one the others. He asks Jack "We aren't going to Guam are we?". :)
As Jack is back in his seat, and he and Ben are talking. Jack tells Ben about the letter and in a rare moment.. Ben does a generous thing. He tells Jack he'll give him his privacy to read the note. He does finally. It says "I wish you would have believed me". Then we see a flash of bright light and Jack wakes up on the island.
After rescuing Hurley and getting to Kate, we hear a vehicle and loud music playing. It's a Dharma VW van. The drivers steps out and points a gun at the 3. Guess who it is? Jin.
Ok.. so some things we have answers for: We know how they get back to is island. We know they all were at least on the flight (minus Aaron). (We don't see Sun, Sayid and Ben on the island yet, so can only wonder if they are also there.) We know that Desmond found Faraday's mom like asked and gave her the message. (Her reply was "I thought that's what I was doing?) We know that Dharma wanted the island because of the magnetic properties (or something weirdly scientific like that) and that they'd been searching for it since the 50's. We also were told by Hawking that the island is & always has been moving. (Just apparently never having time flashes before.)
What we don't know: How did Hurley find out about the flight? (He was carrying a guitar, so possibly Charlie told him?) Where did Sun, Sayid and Ben go? Why was Ben beaten up? Did he try to follow through on his promise to kill Penny? Where is Aaron? Did Kate send him to stay with Sun's daughter and mom? Did she give him away? Or did she give him to Claire's mom? Why is Sayid in handcuffs? Is this maybe because they finally caught up to him for all the assassinations? Why is Jin in a Dharma van, with a Dharma uniform on?
Some other thoughts: I think Jack's granddad, Ray, knows about the island. I think his "escape" from the nursing home was a plan to get Jack there and find the shoes. Maybe Christian "visited" him at some point and told him to get Jack there; I looked on imdb.com and Claire's mom will be in an upcoming episode. So I'm thinking she has Aaron.