It seems to me like real progress is being made now, like we're getting major chunks of mythology downloaded each week, and it shouldn't really be a surprise that this week's episode was written by Carlton Cuse and Damon Lindelof.  As the hosts of this party, it makes sense that they'd be the ones to give us some of the major puzzle pieces.

The "previously on" clips this year are major hints as to what you'll see in the episode each week, and this week was no exception.  First, they show Jack in TIMELINE A at the airport as the guy from Oceanic tells him that they lost his father, and Jack telling Locke about it.  Then we see Dogen meeting the Oceanic survivors, Sayid getting dunked and waking up, and Lennon telling Jack about the pill they want Sayid to take.

They specifically played the exchange between Jack and Dogen, as well.

"There's a darkness growing in him."

"How do you know?"

"Because it happened to your sister."

Then we see Aldo about to shoot Jin, and Claire showing up to shoot Aldo and rescue him.  And with that...

TIMELINE A.  Jack comes home.  Quickly changes clothes.  Washes up.  And as he's getting ready, he sees a scar that confuses him a bit.  It's not new, but it's certainly not ancient.  His mother calls, and she's upset that she can't find Christian's will anywhere in the house.  She wants Jack to help her find it, and he promises he'll come over to do that.  He asks her when he had his appendix out, and she tells him it was when he was young, no more than seven or eight years old.

"You don't remember that?"

"Yeah... I guess I do..."

Does he, though?  Isn't that the scar he got when Juliet did that for him?  The more we see the way these two timelines work, the more questions I have about it all.  I'm sure that's the point, of course.

Jack hurries out of his house and drives to St. Mary's Academy.  There's a teenage boy waiting for him outside on the steps.  Jack refers to him as David, and David refers to Jack as Dad.

Okay, then.

TIMELINE B.  Jack stands staring into a puddle at the Temple.  Dogen walks out to talk to him.  "Your friends... Sawyer and Austin and Kwon... they are not coming back, are they?"

"Probably not," Jack responds.

In the courtyard, Hurley and Miles are playing tic-tac-toe and they tie.  Again.  They decide to get something to eat, and Hurley heads off to find a kitchen.  As he cuts through the room where the pool is, he sees someone sitting on the steps and asks if he knows where it is.  When the guy answers and turns around, it's Jacob.  Hurley's starting to get used to seeing him by this point, and asks what Jacob wants from him this time.

"I'm here because I need you."

"For what?"

"You should probably get a pen."  He tells Hurley that he's going to need him to write down some instructions, and then tells him, "Someone is coming to the Island.  I need you to help them find it."

LOST.

After the first commercial, it's back to TIMELINE A.  David's a pissed-off kid.  He doesn't want to talk to Jack at all.  He keeps his iPod on at all times.  It's time for one of his infrequent visits.  David says they see each other once a month at most.  Jack tries to figure out something they can talk about, and sees that David is reading "The Annotated Alice," one of the many editions of Lewis Carrol's book.  Before Jack can get David to respond, his mother calls again, still upset about Christian's will.  Jack tells David that he has to go out for a little while.  David doesn't seem to care.

TIME LINE B.  Sayid and Jack sit and talk.  Sayid notices that everyone in the Temple is giving him the stink-eye, and he asks Jack to clarify why.  Jack tells Sayid that the pill was poison.  He tells Sayid that whatever's happening to him happened before to someone else.

That's our cue to catch up with Claire and Jin.  She checks the bodies of the Others that she shot, then opens the trap and sets Jin free.  He's really freaked out by her crazy Rousseau-lieke appearance.

"How long have you been out here?"

"Since you all left."

So that's three years she's been on her own.  He tries to get up and walk, and ends up flat on his face, passed out.

Inside the Temple, Hurley walks along a hallway, instructions written all over his arm, following symbols through the place.  Dogen finds him and tells him that he's not allowed to be inside.  What Dogen can't see is that Jacob is standing behind him.  "Tell him you're a Candidate," Jacob says, "and you can do what you want."

Hurley repeats that to Dogen, who is shocked, and Dogen demands to know who told Hurley that.  He walks off, upset by the exchange, mumbling in Japanese, and when Hurley asks Jacob what he said, Jacob tells him he doesn't want to know.  He also tells Hurley that he has to take Jack with him, and when Hurley asks how he's supposed to convince Jack to do that...

... we cut to the courtyard, where Jack is sitting.  Hurley walks up and sits down next to him.  "Be cool, man.  Act natural."  He tells Jack he's going to walk away in ten seconds, and then he wants Jack to follow him.  He tells Jack that Jacob ordered it.  Jack seems totally uninterested in being part of the plan until Hurley says, "You have what it takes."  Whatever that means, it visibly rattles Jack, and he agrees to go with him.

"Fine.  Let's go see Jacob."

After the second commercial, we find Jin back at Claire's camp.  His leg is still bleeding, and she's nowhere to be seen.  He looks around and sees that she's got explosives among her supplies, as well as a crib that holds a very creepy fake baby.  He hears her coming, so wisely leaves the creepy baby doll alone.  When she shows up, she's got Justin with her, the chatty other who was with Aldo.  Turns out he was shot but he's not dead.  That gives her a chance to question him, since she's convinced that Justin and the Others from the Temple were the ones who kidnapped Aaron and who tortured her.

When she goes to get something to help dress Jin's leg, Justin begs Jin to untie him.  He tells Jin that they have to go.  "She's going to kill us both."

Jack and Hurley are out of the Temple by this point, walking together by a river, when they run into Kate.  She tells them that she's looking for Claire, and Jack tells her what Dogen said about Claire.  Jack wants Kate to come with them, but Hurley tells him that Jacob said it was just supposed to be the two of them.  No matter.  Kate's got her own things to do, and they split up once again.

TIMELINE A.  Jack is at his mother's house, and she's really worked up about the missing will.  Jack asks, "Why would he make it easy on us now?"

His mother asks about David, and tells Jack how upset he was at Christian's funeral.  Jack didn't realize.  He talks about how he has trouble communicating with David, and she tells him that it runs in the family, reminding him of how much trouble Jack had talking to Christian when he was young.  They find the will, and she opens it to read, stopping quickly because she's troubled by something.  "Jack, did your father ever mention a Claire Littleton?"

TIMELINE B.  Justin is desperate for Jin to help him escape.  Claire comes back and interrupts them, and she starts stitching Jin's leg.  She wants her baby back, and she tells Justin that she knows he and the Others have him.  She says her father told her, and that her friend told her, too.  Justin asks her what friend she's talking about.

She deflects the question by asking, "You're still my friend, aren't you, Jin?"  Jin agrees that he is, and she finishes patching up the leg.  Axe in hand, she turns to Justin.  "Okay.  Now it's your turn."

Another commercial, and then we're back to Jack and Hurley.  Hurley apologizes for screwing things up with Kate and Jack by the river, and Jack tells him not to worry about it, that anything that might have happened between him and Kate ended a long time ago.  Hurley asks what happened to end things, and says he thinks Jack would have made a great father, an idea Jack roundly rejects.

They find an asthma inhaler on the ground, and Hurley recognizes that it was one of Shannon's.  They realize where they are... the cave from Season One.  They walk inside, where the dessicated bodies of Adam and Eve are still lying on the floor.  Hurley plays the "what if" game for a moment, talking about time travel and asking, "What if these skeletons are us?"  It's hilarious how Hurley is pretty much the audience's voice this season. 

Jack tells Hurley how he found the cave in the first place as he looks at the shattered remains of Christian's coffin.  "I was chasing the ghost of my dead father."

TIMELINE A.  Jack brings a pizza back to his place and finds David gone.  There's not even a note waiting for him.  Jack tries calling his cell phone, but there's no answer, so he goes over to David's mother's house.  She's out of town, so Jack lets himself in with the spare key and checks David's room.  He finds sheet music and a keyboard and seems surprised.  He checks David's answering machine.  There's a message from the Williams Conservatory, confirming David's audition for Friday night at 7:00 PM.  Jack checks his watch, sees he can still make it.  There's one other saved message, which turns out to be Jack's call from Australia after learning about Christian's death.  "I just needed to hear your voice."

TIMELINE B.  Again, a bit of meta Hurley dialogue as he and Jack continue to walk together.

"This is cool, dude.  Very old school."

"What?"

"You and me, trekking through the jungle to do something we don't quite understand.  Good times."

Hurley asks why Jack came back, and Jack asks him the same thing.  Hurley says he came back to the Island because Jacob told him to, which makes Jack laugh a little bit, which in turn makes Hurley defensive.  He asks if Jack has a better reason for coming back.

"I came back here because I was broken.  And I was stupid enough to think this place would fix me."  When Hurley tries to express concern, Jack shrugs him off.

They get to another beach, where they find what Jacob sent them looking for:  an ancient lighthouse.  Jack asks what we're all thinking.  "How have we never seen it before?"

"I guess we weren't looking for it."

Meanwhile, Claire's worked herself into a frenzy, and she's ready to kill Justin.  Jin stops her by telling her than Kate took Aaron away from the Island and has been raising him.  Claire kills Justin anyway with an axe in the gut.

After the commercial, we're back to the Lighthouse.  Hurley says they have to go turn it on, and so Jack kicks in the door.

TIME LINE A.  Jack makes it to the Williams Conservatory in time to hear David perform and, as it turns out, he's amazing.  Jack is moved to tears by the performance.  When he finishes, an Asian kid standing nearby asks, "Is that your son?"

"Yes."

"He's really good."  The kid walks away and talks to his own dad.  When Jack goes to leave, the dad stops him.  It's Dogen, and he asks Jack how long David's been playing piano.  Jack has to confess that he doesn't know.

TIMELINE B.  Hurley and Jack make it to the top of the Lighthouse.  Hurley starts turning the wheel that points the mirrors.  "Tell me when it gets to 108 degrees," he says.

Jack looks over at the mirrors and starts getting glimpses of distant places.  He looks down at the wheel that Hurley's turning and sees that each degree has a different name written by it.  He sees many familiar names, including his own.  He orders Hurley to turn it to 23 degrees.  Hurley tries to protest, but Jack takes the wheel and turns it himself.  Once it's there, Jack looks in the mirror again.

He sees his childhood house.  The place where he grew up.

Jack realizes Jacob's been watching them all their whole lives.  He tells Hurley that he wants to talk to Jacob immediately, and Hurley protests that it doesn't work that way.  Jack picks up a large iron bar and approaches the mirror, furious.

"Uhh... what are you doing, dude?"

"Why was he watching me?"

"I don't know."

"Why is my name written down on this thing?"

"He didn't tell me."

"WHAT DOES HE WANT FROM ME?"

"I DON'T KNOW, JACK!"

And so Jack breaks all the mirrors.  And walks away.

One last commercial break.  TIMELINE A.  Jack catches up with David outside the Conservatory.  "You were great in there," he tells him.  David's surprised to see him.  Jack asks why David has been hiding the fact that he's still a musician.  David says he was worried about how interested Jack was in his music, and he didn't want to fail in front of Jack.  This hits Jack hard.

He tells David that when he was a kid, he was always worried about disappointing Christian.  He tells him that Christian used to say to him, "You don't have what it takes."  He tells David that he never wants him to feel like that, and that he just wants to be part of David's life.  They go home to have pizza together, truly reconciled.  It's a lovely moment between the two of them, and really pays off Jacob's comment earlier that baited Jack into joining Hurley at the Lighthouse.

Speaking of which... in TIMELINE B, Jack sits outside on a bluff, looking at the ocean.  Hurley stands by the Lighthouse by himself.  Jacob appears.  Hurley's pissed at him at first, but realizes that the entire errand was about Jack.  Jacob says Jack has to figure out what's required of him, and he'll have to make his own choice when he's ready.

Jacob says he also needed to get the two of them away from the Temple, since someone bad is on their way there right now.  Hurley wants to go warn everyone, but Jacob stops him.  "It's too late."

Jin, still stunned that Claire actually killed Justin, tells Claire that he was lying and that Kate never took Aaron off the Island.  He says Aaron's in the Temple, and that he just saw him there.  He offers to take Claire there, and that he knows a way in.

She tells Jin that it's a good thing he was lying, because "If Kate was raising Aaron, I'd kill her."

Just then, Alterna-Locke shows up.  Jin seems shocked.

"John?"

"That's not John," Claire says.  "That's my friend."

Smiles all around.

BOOM.  LOST.

Big week.  And the tease for next week was just plain cruel.  I'm not sure what anyone else felt about tonight, but so far, this season seems like the fulfillment of the promise, and I'm excited to see what big chunk of stuff we get next week, and to see how these timelines are going to collide.  Because more than ever, I'm sure that there's a merge coming, and that it's not going to be easy for anyone.

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