It's fish-out-of-water time as the ladies travel to the rainforest of Costa Rica. Zip lining through the jungle canopy has the O.C. ladies screaming with excitement, while their shifting friendships have them screaming at each other. Vicki's erratic behavior has the others worried that she's having a mental breakdown, while the collective whip comes down hard on Alexis as the group conducts a "makeshift intervention" to confront her on her phony lifestyle.

Alexis faces her biggest test yet: reporting on-location for her final Fox 5 news segment, while Vicki pushes Brooks to fix his teeth. Meanwhile, Gretchen accidentally uncovers Slade's plan to propose, leading to a confrontation that puts them over the edge. Then, Tamra gets a shock of her own when Eddie surprises her with a romantic trip to Bora Bora, leaving her wondering what he's got up his sleeve.