Two main storylines: Sun and Jin (finally!); and then the camping expedition (Desmond, Hurley, Charlie and Jin) who found the helicopter pilot (who is not Penny) hanging from the trees in the jungle.
Sun and Jin - present day. Jack, being the take-charge doctor-guy that he is, checks in with Sun about her pregnancy: feeling well? no cramping? no bleeding? Sun gets suspicious and asks Kate if Jack can be trusted after his week-long Camp Other vacation. Kate hedges, then 'fesses up that Juliet is a fertility doc and that the Others have had pregnancy issues. Sun asks Juliet what the deal is and Juliet admits that 9 out of 9 women who got pregnant on the Island have died; only Claire, who got knocked up before her arrival, has survived. But, wait! Sun doesn't know if the baby is Jin's (conceived on-Island) or the dead boyfriend's (conceived off-Island). Juliet says there is a sonogram machine in the medical hatch and she can determine when Sun got pregnant. Kate pipes up: but we went there and there was nothing! Juliet: you didn't know where to look. Sun and Juliet go to the med-hatch; Juliet uncovers a hidden room with a sonogram and all the nursery stuff (cradle, rocking chair, etc.). Sun asks why is this room hidden? Juliet: Because it's where all the Other mothers died. They get going on the sonogram: the Losties have been on the Island 90 days, the baby was conceived 8 weeks ago, ergo, Jin is Sun's baby daddy. Sun cries, first because yay! her husband is the father! And second because – ack -since her husband is the father, she's got about two months before she and the baby die, Island-style. Sun and Juliet head out back to the beach, but Juliet scurries back to make sure the secret room is hidden again, and records a taped message for Ben updating him on her progress monitoring the female Losties’ reproductive status. She turns off the recorder before saying “I hate you;” I’m pretty sure I would have left that part in. I mean, he knows anyway.
Sun and Jin - flashback. The flashback takes place in Korea, not long after they get married but before Jin is forced to be a bad-ass for Sun's papa. Sun is out and about town and is approached by an older woman who knows who Sun is (i.e., powerful local family), that Jin's dad is a fisherman, and also that Jin's mom is a prostitute. Oops! Sun didn't know that last part! The old lady blackmails Sun for 100K to keep this a secret. Sun knows that Jin tells everyone both his parents are dead, being ashamed of his dad’s profession, and his father told him that his mother is dead. Exposing all of this to be a lie would bring big shame. So Sun goes to see Jin's dad who is lovely and sweet and who makes a point to wipe off his fisherman hands before shaking her hand. He admits that Jin's mom was a big ho – he’s not sure Jin is even his own child - but since she left him with the baby, he raised Jin as his own. Sun then goes to see her own father and asks for the 100K, not explaining why. Her dad says that if the money is for Jin, then Jin will have to work off the debt: "he works for me now." And thus we learn how Jin ended up having to be a thug - not even his fault! Sun pays the old lady and tells her: I know you're Jin's mother and if you ever try this again, you'll see how powerful my family really is. Nice! I love it when Sun gets tough.
Camping expedition. The four jungleteers have cut down the pilot who is not Penny, but who recognizes Des and speaks about a jillion different languages. She's pretty delirious and they find that this is because she's got a big stob sticking out of her side and bleeding profusely. They obviously can't move her, so Des wants to run back for Jack. Charlie points out that it's an 8-hour walk each way. Suddenly, from out of the underbrush, Mikhail (the one-eyed Russian Other whose house Locke blew up and who Locke fried in the sonic/electro-fence) appears! It looks like it's going to be a beat-down, but luckily Mikhail is a field-trained medic. Gosh, that’s convenient. He offers to help the pilot but if he does, they have to let him walk away. Des says it’s a deal; Charlie says we can't let him go after how many of us the Others have killed; Des says by his count, the Losties have offed way more Others than the Others have killed the Losties, if you know what I mean. Mikhail patches up the pilot and leaves, saying that she should be fine in 1-2 days because of the Island miracle cure tendencies. As Mikhail leaves, Jin notices that he's stolen the pilot's sat-phone. Jin runs after him and works some awesome jungle-fu on his patched-eyed butt. When Des and Charlie catch up, they get the phone back but let Mikhail go. They do wonder about the fact that Locke obviously didn't kill this guy in the fence like we'd thought. (Hmmm – it seems as though Locke is one of the only Losties who has never killed anyone. No wonder the Island likes him.) The four jungleteers go back to the pilot who wakes up and asks where she is. Hurley says: Dunno, some Island, but we're the survivors of Oceanic 815. The pilot says: no, no, not 815, they found the plane and there were no survivors - everyone died on 815*. Hurley: huh?
* This is my husband's theory: that everyone on the flight died but the Island is some kind of limbo/purgatory so they're all stuck there until they pass some test that the Island hands out.
49 minutes ago