Here is a summary of the spoiler from the recent EW Scans.FLASHES BEFORE YOUR EYES
Back on the beach, the Oceanic 815-ers will finally be dealing with the aftereffects of Desmond turning the fail-safe key, which imploded the hatch and lit the sky purple. In episode 8, the lovelorn Scottish soldier — new and improved with precognitive abilities! — informs a central character that he or she will die; he is also the subject of a flashback device employed "in a way we never have before and never will again," hints Lindelof. "It'll either blow people's minds or chase them away for good."
ENTER 77
The Others' connection to that utopian weird-science project, the Dharma Initiative, is slated to be revealed in episode 11 (March 7), which also features a visit to a new hatch dubbed the Flame. Carlton Cuse: "The connection between the Others and Dharma gets revealed in episode 11. We will be visiting another Dharma station soon. But the map becomes less important, because when they visit this new station, they'll be getting some new information that helps them understand where the Dharma people lived and where their stations are."
EPISODE 13 - Locke Centric
[Scenes from episode 13 include] Juliet pushing Ben in a wheelchair, and Jack cheerfully lobbing a football to his sworn enemy Mr. Friendly. "Everyone should be wondering what the hell is going on," explains Fox during a break. "Has Jack been converted by the Others? Drugged? Is he pretending? All sorts of scenarios could be happening here." We will find out how Locke ended up in a wheelchair. "I was afraid it'd be anticlimactic," says O'Quinn. "It's not. It's pretty stunning. You're gonna go, 'Man, no wonder this guy wants to stay here!'" Also, the castaways discover that the Others possess a submarine.
EPISODE 14 - Paulo & Nikki centric
Flashbacks will center around Nikki and Paulo. While even Lindelof acknowledges that Nikki and Paulo are "universally despised" by fans, that's going to change, he vows: "We had a plan when we introduced them, and we didn't get to fully execute that plan. But when the plan is executed, Nikki and Paulo will be iconic characters on the show."
Source: Entertainment Weekly