Seth and Kirsten want to avoid facing the world after their respective displays at Thanksgiving. Sandy has some advice for Jimmy, which doesn't sit well with Julie. Ryan and Luke find themselves getting along after an O.C. loved-one comes out of the closet to face negative reactions.

Jimmy and Sandy run into a roadblock in their effort to re-open the Balboa Lighthouse restaurant. Summer and Seth take it upon themselves to finally make Marissa feel more at home at Jimmy's. Everyone is shocked when Caleb makes a proposal, which sparks a near-fatal accident for Luke. Marissa, and Sandy and Jimmy each strike deals with Caleb. An old O.C. friend moves away.

The summer is coming to an end, and Seth hasn't returned home to Newport. In the midst of home renovations, Sandy and Kirsten are strained and missing their son. Ryan has begun his new life with Theresa in Chino, as Marissa is alone and in a dark place. Summer is slowly getting over Seth.