The O.C.

When tough, guarded, fiercely intelligent 16-year-old Ryan Atwood (series star BENJAMIN McKENZIE) is arrested for participating in a car theft, idealistic pro-bono public defender Sandy Cohen (series star PETER GALLAGHER) is assigned to the case.

Now that Ryan's mother has abandoned Ryan and moved away, Sandy has no choice but to accede to Kirsten's wishes and remand Ryan to Social Services. Facing the prospect of living in a foster home, Ryan prepares to secretly leave on his own. But Seth finds out and suggests a better idea.

Kirsten's company does not charge Ryan with arson for the model home burning, but he must remain in juvenile hall until he can be placed in the care of a guardian.

The teens attend cotillion, where a fight breaks out.

After befriending a likeable busboy, Donnie (PAUL WASILEWSKI), at a casual seafood restaurant, Ryan takes a job there.

Kirsten nervously prepares a magnificent birthday party for her widowed father, Caleb Nichol (recurring guest star ALAN DALE), an extremely successful and driven businessman for whom Kirsten works. She is devastated when, rather than being proud of her hard work while he was out of the country, Caleb berates and demotes her for making deals without his approval.

It's the end of summer, and Seth convinces a reluctant Ryan to plan a trip to Tijuana, where hundreds of rowdy teens congregate to indulge in escapist excess before they have to begin school again. In addition to dating Luke again, Marissa is angry with Ryan after witnessing him with an older woman. She also wants to stay home and take care of her overstressed father. But Summer persuades her to c

Ryan risks his future to keep Marissa from being sent away.

The summer is officially over, and it's the first day of school. Summer (recurring guest star RACHEL BILSON) still ignores Seth in public, but privately she is jealous of Seth's burgeoning relationship with iconoclastic East Coast girl Anna Stern (recurring guest star SAMAIRE ARMSTRONG). And Summer isn't the only person fighting feelings of jealousy. Kirsten still isn't comfortable with Sandy's fr

Having seriously dated for one week, Marissa and Ryan are progressing slowly.

Seth gets in trouble choosing between Summer and Anna.

After Thanksgiving, Anna (recurring guest star SAMAIRE ARMSTRONG) and Summer (recurring guest star RACHEL BILSON) remain upset with Seth for his behavior on the holiday, and Seth struggles to reconcile with them. Meanwhile, Julie (recurring guest star MELINDA CLARKE) has relationship problems of her own. Jimmy and Sandy team up to tackle Jimmy's legal issues.

Seth excitedly introduces a skeptical Ryan to Chrismukkah, a Cohen family tradition that resulted from Kirsten being Christian and Sandy being Jewish.

Kirsten's rebellious 25-year-old sister, Hailey Nichol (recurring guest star AMANDA RIGHETTI), comes to town on New Year's Eve, causing turmoil in the Cohen household.

Kirsten's unemployed sister, Hailey (recurring guest star AMANDA RIGHETTI), moves in with the Cohens and disrupts the entire family when she behaves as the houseguest from hell.

When Oliver almost overdoses, Marissa stays with him.

Sandy and Jimmy begin a new business partnership when they buy The Lighthouse, a beloved Newport restaurant.

Ryan and Luke ally to protect Marissa from Oliver.

Marissa tries to reconcile with Ryan, but he can't forgive her.

Marissa and Ryan try to start over as friends, but it's not as easy as they had hoped.

When Anna plans to move away, Seth tries to stop her.

When actor Grady Bridges (COLIN HANKS - "Orange County," "Roswell") invites Summer and Marissa to his birthday party, the girls take Ryan and Seth to Los Angeles to join in the festivities.

The Cohen family prepares for a visit from Sandy's mother, Sophie (LINDA LAVIN - "Alice"), for Passover dinner.

Marissa isn't ready to speak to Luke or her mother, Julie, following her discovery that the two have been having an affair. Luke is desperate to explain himself. When he gets into a near-fatal accident, however, both Marissa and Ryan decide to listen to what he has to say. Meanwhile, it's opening night for new restaurant The Lighthouse. Just prior to opening, Jimmy and Sandy are shocked to find ou