|← S3||The OC Season 4|
|#01||"The Avengers"||#7||"The Chrismukk-huh?"||#13||"The Case of the Franks"|
|#02||"The Gringos"||#8||"The Earth Girls Are Easy"||#14||"The Shake Up"|
|#03||"The Cold Turkey"||#9||"The My Two Dads"||#15||"The Night Moves"|
|#04||"The Metamorphosis"||#10||"The French Connection"||#16||"The End's Not Near, It's Here"|
|#05||"The Sleeping Beauty"||#11||"The Dream Lover"|
|#06||"The Summer Bummer"||#12||"The Groundhog Day"|
Seth tags along with Ryan who travels to Enseniada, Mexico to look for the fugitive Volchok, and tries to hold off Ryan from doing something drastic. Back in Newport, there is a clothing drive at Harbor High, where Julie persuades Kaitlin to participate in it, until she learns Kaitlin's true agenda. At Brown University, Taylor pays Summer a surprise visit, but does not want to confide in her about her problems of her own back in France.
Ryan goes to Ensenda,Mexico to take revenge on Volchok. Seth tags along, refusing to allow Ryan to ruin his life by committing murder. After leaving a coded note, Seth calls his parents, informing them of what's going on. In Mexico, Ryan tries to find Volchok but fails, while Seth tracks him down and gives Ryan false information about his whereabouts.
Summer is trying to save a tree with Che when Taylor pays her a surprise visit, telling her that she needs to sort things out with Seth. Summer, in denial, asks Taylor why she's back from France and they have an argument. Just before Taylor leaves, she adds that she got married in France. Summer tries to write a letter to Seth but can't find the words.
Kaitlin has problems at school and gets caught stealing clothes at a clothing drive at Harbor.
Sandy and Kirsten go to Mexico and bring Ryan and Seth back. Sandy tells Julie that he knows about her giving information to Ryan, and finally, Seth realizes that he really damaged his friendship with Ryan by 'betraying' him to his parents.
Sandy: We're doing the right thing in trusting them.
Kirsten: I know.
Sandy: They're adults. We couldn't have stopped them if we tried.
Kirsten: I know.
Sandy: I'm going to Mexico.
Kirsten: I'm going with you.
Sandy: You told Ryan where to find Volchok. Even for you, this is a new low.
Julie: Okay, you know what? You're crazy. I'm just going to say goodnight.
Sandy: You sent Ryan down there to commit a murder. I could have you arrested.
Julie: But then, you'd get Ryan arrested too. And you're not going to do that, are you?
Sandy: If anything had happended to him or to Seth...
Julie: [cutting him off] Okay it's late, and I'm not in the mood for threats.
[Julie gets up to leave]
Sandy: Sit down!
Sandy: After everything our families have been through, you would put our kids in danger?
Julie: At least you still have all your kids.
- Ben McKenzie as Ryan Atwood
- Melinda Clarke as Julie Cooper
- Peter Gallagher as Sanford "Sandy" Cohen
- Rachel Bilson as Summer Roberts
- Kelly Rowan as Kirsten Cohen
- Autumn Reeser as Taylor Townsend
- Adam Brody as Seth Cohen
- Willa Holland as Kaitlin Cooper
- Cam Gigandet as Kevin Volchok
- Chris Pratt as Che Cook
- Michelle Ongkingco as Amber
- Wayne Daglish as Brad Ward
- Corey Price as Eric Ward
- Tia Carrere as Dean Torres
- Steve-O as Marine