Edna found out (thanks to Brandon) that she's not part of the main alliance in her tribe, so she's decided to continue cozying up to Coach and hope that he saves her. They go look for coconuts together and Coach interviews that he really likes Edna and feels comfortable with her, and he plans to keep her and get rid of Mikayla, since they're both outside of "The Six." Six people seems like a huge alliance. Coach tells Edna about that, and Edna vows to "follow [Coach] into battle... even if it gets ugly." Man, she is really feeding into Coach's Daddy fantasies. Gross.
Hey, what's Ozzy up to? Still whining and crying? Surprisingly, no. He's realized that he threw a temper tantrum, and decides to talk to Keith and hope that they can still work together. He doesn't actually apologize, but he says he's "willing to look past it" (meaning the blindside), and Keith agrees that they should continue to work together. So then Ozzy goes back to the rest of the tribe and actually does apologize, saying that he's sorry he flew off the handle, but then claims that he told them about the Idol to try to unify the tribe. Well, that's not really true, but it's pretty to think so. Jim is no dummy, and realizes that Ozzy is only doing this because he's figured out that he has nowhere else to go since they're probably not merging any time soon. So Jim is happy with his position in the competition, since he's got Ozzy to help him win challenges, but also has a slightly-humbled Ozzy.
It's Day 16, and time for the Immunity Challenge. Once both tribes arrive and assemble, Probst explains the details. They will have to assemble a wheelbarrow, fill it with coconuts, and maneuver it through an obstacle course, dumping the coconuts in a trough, and then go back for a second load of coconuts. Then the second half of the tribe has to take the wheelbarrow apart, and use the pieces to create a slingshot, which they will use to shoot coconuts at targets. First tribe to knock down all of the targets wins immunity and reward. Edna is useless and will sit out for Upolu.
In the first half, Upolu has Brandon, Sophie, and Rick working the wheelbarrow, while Ozzy, Dawn, and Cochran do the same for Savaii. They get their wheelbarrows assembled at about the same time. Brandon and Rick fly through the course together with the wheelbarrow, but Ozzy and Dawn struggle. I think the problem is that Ozzy is trying to do the whole thing himself instead of trying to work in concert with Dawn. So Upolu gets all their coconuts dumped and their slingshot assembled, while Savaii is still trying to get their second load of coconuts. When Savaii tries to dump their second load of coconuts, Ozzy tries to do the whole thing himself, which doesn't work, and Cochran "tries" to "help" but seriously isn't doing anything at all. Useless.