The O.C.

The friends worry as the cops want to know who shot Trey.

Sandy worries about Kirsten's friend. Marissa gets bad news.

Julie and Sandy keep Ryan and Marissa apart, but Seth and Summer help them enjoy a night to remember. Taylor catches them in the act. Caleb's will disappoints Julie and Jimmy.

Marissa adjusts to a new school. Ryan wonders if their separation will affect their relationship. Seth's feud with Dean Hess gets Summer in trouble. Charlotte arrives in Newport.

Ryan makes a life-changing decision with Sandy's support.

Taylor (recurring guest star AUTUMN REESER) ruins Seth's night when she throws a Harbor School event that keeps Summer at a distance. Marissa's new friendships at public school worry Summer, and she enlists Ryan's help. Meanwhile, Sandy works on a plan for the Newport Group and forms a new partnership. And Charlotte (recurring guest star JERI RYAN) convinces Julie and Kirsten to edge back into New

During a show by rock band THE SUBWAYS, Taylor's behavior causes a major rift between Seth and Summer. Marissa is determined to end the conflict between Ryan and Volchok.

The friends plan their futures. Julie returns to her roots.

Ryan works an internship for Sandy. Summer and Seth try to impress Brown University. Johnny reveals how he feels about Marissa. Ryan and Marissa tell each other the truth.

After the teens spend hours picking out the perfect Christmas trees, they devise a special plan to help a friend in need. Meanwhile, missing her mom, Summer feels even more somber during this holiday, and Johnny's (recurring guest star RYAN DONOWHO) sudden misfortune forces him to take matters into his own hands. Kirsten tries to put the past behind her and make amends with Julie. Reminiscing Seth

The friends try to get Marissa back into their school. Sandy makes a decision that could change Marissa's fate. Summer's father and Julie have been lying to their daughters.

The clan tries to re-create a perfect East Coast Christmas.

Kaitlin stirs up trouble for the gang as she prepares to celebrate her birthday. Sandy encourages Seth about college, but Seth finds a better alternative.

Summer discovers the truth about Seth. Sandy and Matt (recurring guest star JEFF HEPHNER) encounter an obstacle to their hospital project. Kirsten and Julie take their matchmaking business a little too far, causing Julie to go into hiding. Marissa finally tells Johnny (recurring guest star RYAN DONOWHO) how she truly feels. And Kaitlin (recurring guest star WILLA HOLLAND) wonders which Cooper John

Tragedy strikes the friends. Johnny's cousin arrives.

Sadie and Ryan take a trip. Ryan returns to his old ways.

Ryan tries to decide whom to invite to his birthday party.

Ryan's nemesis returns. Sandy experiences business pressure.

Marissa seeks solace with bad boy Volchok and his crew.

The kids receive their college acceptance and rejection letters, forcing them to make some life-altering decisions. Ryan and Sadie (recurring guest star NIKKI REED) try to decide what do after high school, and their decision concerns Sandy and Kirsten. Taylor (recurring guest star AUTUMN REESER) throws a college sweatshirt party at Harbor High School, and Marissa and Summer patch up their friendsh

Ryan visits his mom. Taylor and Summer wonder why Seth is keeping secrets. Julie gives Volchok stern advice. Marissa confronts Volchok's friends and saves a girl.

The friends go to college orientations. Seth sees Anna.

Harbor School's senior prom brings out the best and the worst in everyone. Taylor (recurring guest star AUTUMN REESER) has a great time, while Summer doesn't enjoy herself with her surprising prom date. Seth and Anna (recurring guest star SAMAIRE ARMSTRONG) come up with a plan to win Summer back for Seth. Meanwhile, Marissa convinces Volchok (recurring guest star CAM GIGANDET) to go to the prom wi

Marissa visits Kaitlin at boarding school.