What you've got to know is that everyone on the island seems to be jumping through time, but remaining on the island. And on the mainland, people are just jumping out of their skins about whether or not they should go back to the island.
Ben is getting Jack cleaned up and off drugs and trying to convince him to help round up the rest of the Oceanic Six and get them back to the island. Because of Jeremy Bentham/John Locke's visit to Jack last season, he's already ready, though less than confident. They want to get Hurley too, but learn from the news that Hurley's wanted for murder (committed by Sayid) and has escaped from the psychiatric hospital.
Meanwhile, lawyers representing an undisclosed client go to Kate's house with a court order to collect blood samples from her and Aaron in order to (dis)prove she's Aaron's mother, so Kate takes Aaron and goes on the lam a.k.a. "vacation."
Sun's flying from Korea to Los Angeles, or trying to, when Widmore has her detained. He's sort of like the Godfather. He wants more respect than she gave him on their first meeting. Sun's all, "All right, can I go to L.A. now?" and Widmore's all, "Sure, seeing as how we both want to kill Ben Linus and all."
On the island, Locke was with Richard when the island moved, but then poof -- he was alone, standing in the pouring rain. He sees Eko's brother's plane as it crashes, and tries to climb up the vines to see if there are any survivors but someone on the ground shoots him in the leg. It's Ethan, who doesn't recognize Locke because he hasn't met him yet. Just when he's about to kill Locke, poof -- Ethan is gone too, and Locke's lying beside the long since burned out wreckage of the plane. Richard meets up with Locke again, tends to his wound and gives him a compass, because the time they meet, Richard won't know Locke. Confused? Excellent. That means you've been paying attention.
Elsewhere on the island, Daniel Faraday tells the rest of the castaways and other various stranded people (I'll call them all strand-aways) to think of the island as a record, and right now, it's skipping. They are all "dislodged from time" which is why their camp has disappeared without a trace. It's also why -- sometimes -- after a bright white flash, the hatch is still all blown to pieces and other times it is back in its original recipe with Desmond locked inside, furiously punching in the numbers. Daniel stops Sawyer from getting into original-recipe hatch and seeking out Desmond's help (and some supplies) and lectures him on the rules of time travel. After Sawyer, Juliet, and Miles leave to go back to the beach, Charlotte's nose starts bleeding and Daniel freaks. He tells her to follow Sawyer, Juliet and Miles, and then bangs on the door and gets Desmond to open up. Desmond doesn't recognize him, but Daniel tells him he's the only person who can save them all because the rules don't apply to him (Des). Daniel tells Des that if the helicopter ever comes and ever gets him back home, then Des has to go to find Daniel's mother at Oxford, her name is…
Desmond wakes up with Penny -- in the present -- and tells her he was back on the island. Pen reminds him that was three years ago and says he must have been dreaming. Desmond says it wasn't a dream, it was a "memory" and that they have to go to Oxford.
There's a flashback to right after the escape. Aboard Penny's boat, Searcher, Jack is convincing Desmond, Penny, Frank (the helicopter pilot) and the rest of the Oceanic 6 to tell the big lie about how they're the only survivors, so Widmore doesn't kill the strand-aways. Hurley doesn't want to lie, and thinks if all of them come clean, they can get help for their friends, but no one will back him up, not even Sayid. Hurley tells Sayid he'll remember how Sayid didn't have his back, and he'll do the same to him, someday.
In the present, Hurley and Sayid are on the run, but the safe house Sayid takes Hurley to is not so safe, and Sayid gets shot with tranq darts. Hurley flees with the unconscious Sayid and gets pulled over by the cops. Oh, wait. It's not the cops. It's Ana-Lucia (!!!) who tells him she's not real. She inspires him to get himself together and get Sayid to someone he trusts, and to be smart and not get caught. As she walks off, she says, "Libby says hi," and completely undermines whatever confidence and determination Hurley was just starting to summon. Nice work, Ana-Lucia. She and her cruiser vanish, on account of not being real, or time travel. Hurley turns to the unconscious Sayid, says, "Well, you heard her," and starts his engine for his wild ride.