The OC

Troubled teen Ryan moves from a bad neighborhood to the Cohen home in affluent Orange County. Sandy and Kirsten are glad Ryan befriends nerdy son Seth. Ryan likes neighbor Marissa.

Kirsten doesn't want Ryan permanently, so he buys a bus ticket. Ryan, Seth and Marissa hide in a model home, but Summer finds out and causes trouble with a bully who fights Ryan.

Kirsten takes temporary custody of Ryan. Jimmy borrows money from Kirsten. Summer uses Seth for good luck at a casino benefit. Ryan's mom drunkenly embarrasses him and then leaves.

Kirsten takes temporary custody of Ryan. Jimmy borrows money from Kirsten. Summer uses Seth for good luck at a casino benefit. Ryan's mom drunkenly embarrasses him and then leaves.

Ryan is matched with Anna for cotillion, but he ends up taking Marissa. Summer abandons her intended escort, Seth. Jimmy admits his financial trouble. A fight happens at the event.

Ryan protects Seth at a party in a bad neighborhood. Ryan again must save him after Seth invites the same people to a party in Newport. Luke is shot. Broke Jimmy has a hard choice.

Kirsten has trouble working for her driven father. Julie demands a divorce. After Caleb's hot girlfriend seduces Ryan, Marissa has sex with Luke, who is nicer since being shot.

While Kirsten and divorcing Jimmy paint his new home, they kiss. Sandy considers a job. In Tijuana with the other teens, Marissa finds out about her parents' divorce and overdoses.

Sandy takes a lucrative new job for an attractive woman, which bothers Kirsten. Ryan leaves a placement test in order to help Seth and Summer save Marissa from being sent away.

Summer is secretly jealous of Seth's relationship with Anna. Sandy works on a lawsuit against Caleb's company, bothering Kirsten even more. Ryan fights with Luke over Marissa.

Marissa and Ryan begin dating. Summer tries to deny her feelings for Seth as he gets closer with Anna. Kirsten and Sandy continue to clash. Julie reveals a new relationship.

Seth gets in trouble choosing between Summer and Anna. It's a Thanksgiving to remember as Ryan takes Marissa to visit his brother in prison while angry Julie and the others wait.

Anna and Summer are upset with Seth. Julie has love problems. Sandy helps Jimmy with legal issues. Kirsten's indiscretion is exposed. Ryan and Luke form an unexpected alliance.

Seth introduces Chrismukkah, a Cohen family tradition combining Kirsten's Christianity and Sandy's Jewish heritage. Seth juggles two girls. Kirsten's issues with her father worsen.

Kirsten's rebellious sister causes turmoil by hosting a huge party in the Cohens' house on New Year's Eve. Marissa goes to another party, but Ryan rushes to kiss her at midnight.

Disruptive Hailey refuses to leave the Cohen house. Seth chooses Anna. Ryan is jealous of Marissa's troubled new friend, Oliver. But Ryan later helps Oliver get out of trouble.

Summer tries to annoy Seth and Anna. Oliver irritates Ryan. When Oliver almost overdoses, Marissa stays with him. Hailey moves out. Jimmy and Sandy go into business together.

Sandy and Jimmy buy a restaurant. Kirsten and Julie become workmates. Seth's jealousy of Summer's new boyfriend gives him doubts about dating Anna. Ryan loses control over Oliver.

Caleb forces Kirsten to terminate Julie. Sandy and Kirsten question taking in Ryan. When Ryan and Luke ally to protect Marissa from Oliver, she discovers the truth about him.

Marissa tries to reconcile with Ryan, but he can't forgive her for Oliver. Ryan's ex-girlfriend from Chino arrives for Valentine's Day. Seth and Summer escalate their friendship.

Marissa and Ryan try to start over as friends. Theresa wasn't honest about why she's in Newport. Summer won't acknowledge Seth at school. Sandy is in another mess created by Caleb.

Ryan is glad Theresa will stay in Newport. Julie and Luke's secret affair is threatened when Jimmy sees them. When Anna plans to move back to Pittsburgh, Seth tries to stop her.

Summer loves being with an actor (COLIN HANKS), to Seth's chagrin. But Summer minds when Seth meets a sexy girl (PARIS HILTON). Ryan hides Luke and Julie's affair from Marissa.

When Sandy's mother (LINDA LAVIN) visits, Seth fears she'll disapprove of Summer, who tries to prove him wrong. Marissa runs off when she finds out about Luke and Julie's affair.

Marissa is still mad at Julie and Luke. Luke gets in a near-fatal accident. Sandy makes a choice when he can't get a liquor license because of Jimmy. Caleb proposes to Julie.