Desmond asks about the suit, and Clancy says he wears it so he doesn't get infected. And oh! That reminds him! He goes to the vaccine cabinet, and tells Desmond to give himself a shot of the stuff every nine days. That is, if it's not too late, given Desmond seemed to have been out there a while when they found him.
Back in the present, Desmond asks who the huge angry dude pounding on the door is. "His name is Mistereko," says Locke, and Desmond wants to know why Mistereko carries around a stick covered in scripture. Locke tells him it's because Eko's a priest, as though that explains anything. "We locked out a priest?" says Desmond, seeming quite concerned about this.
Eko finally gives up on beating his fist bloody against the blast doors, and skedaddles out the hatch the old-fashioned way -- via rope up the shaft with the broken ladder. Must be his first time there, because he notices the underside of the hatch door -- placed cinematically just so on the surface -- with the stenciled QUARANTINE in black letters. And he runs off through the jungle.
He's so desperate that he's willing to turn to Charlie to help, even interrupting yet another audience-less Charlie Pace of Driveshaft solo concert on the beach. "Do you know how they got the hatch door open?" he frantically asks Charlie, who says he doesn't but if Eko hums a few bars, he could probably play it. Eko summons all of his willpower to not grab Charlie's guitar and smash it down on his hobbit head, and asks again. "They blew it up. Why?" says Charlie, as though it's self-evident. Well, maybe it is, given the state of the door. Eko says he needs Charlie's help, but Charlie snidely notes that he now appears to be back in Eko's good graces. Eko's got no time for Charlie's grudge, and just tells him about being Locked out of the hatch and how he's absolutely certain that if the timer runs out, everyone will die. "All right, I'm in," says Charlie, after considering it a moment. I'm thinking it's not so much because he believes everyone will die -- because if he does, way to TAKE YOUR TIME THINKING ABOUT HELPING, Charlie -- but because he wants to help thwart Locke.