The O.C.

Kirsten's anxiety over Seth reaches the breaking point; Caleb becomes increasingly paranoid.

Seth and Ryan hope to win back the attention they once had from Summer and Marissa. Hailey tells Jimmy her plans. Sandy explains that the district attorney is watching Caleb.

Seth gets help proving that his friends don't know him as well as they think. Summer gives some thought to how she really feels. Ryan has a confrontation with new classmate Lindsay.

Seth and Sandy embark on new eras and vow to take the whole family with them. Ryan and Seth go on an awkward double date. Julie is overwhelmed by her new role at the Newport Group.

Seth, Ryan, Summer and Marissa attend the SnO.C. Winter Ball. Julie and Jimmy spend quality time together as committee chairs, and Sandy gets closer to the truth Caleb has been hiding.

The whole gang is invited to Chrismukkah at the Cohens' house, but Seth's favorite holiday is nearly ruined as secrets are revealed. Summer, Marissa and Ryan plan to save Chrismukkah.

Ryan tries to come to terms with his feelings for Lindsay. Caleb learns the charges against him were dismissed. Seth cultivates a "bad boy" image. Marissa is angry with Jimmy.

Lindsay and Ryan grapple with their new relationship. Summer meets Zach's family, and it doesn't go so well. Sandy surprises Kirsten with a serenade. Marissa ends up alone.

Marissa and Summer include Lindsay in a girls' night out. Ryan, Seth and Zach bond over video games and pizza. Julie and Kirsten collaborate on an idea for the Newport Group.

Seth and Zach decide to create a comic book. Sandy helps an old friend find his daughter, but more questions arise. Ryan tries to help Lindsay satisfy her curiosity about Caleb.

Summer decides to take an active role in creating the comic book. Sandy and Rebecca reminisce. Meanwhile, Caleb decides what kind of future he wants to have with his daughters.

Sandy tries to make amends with Kirsten. Zach, Summer and Seth pitch their comic book idea. Ryan wants to spend Valentine's Day with Lindsay, but her loyalty to Caleb gets in the way.

Kirsten grows impatient with Sandy's absences and visits Rebecca. Alex invites Marissa to hang out with her friends. Caleb decides to remove all doubt that Lindsay is his daughter.

Marissa tells Julie that she and Alex are dating. Summer is faced with a decision. Ryan convinces Lindsay to take the paternity test. Sandy is stranded in a motel room with Rebecca.

Marissa joins Summer, Seth and Ryan at the mall. Julie is visited by Lance, an opportunistic man from her past. Meanwhile, Sandy and Caleb bond over their recent experiences.

Seth is determined to bring back the spirit of last year. Marissa enlists an unlikely partner to help with the school bonfire. Sandy helps Julie keep her blackmailer at bay.

Someone from Ryan's past comes for a visit. As Marissa and Ryan explore their newfound friendship, Seth and Summer face unforeseen news. Julie looks to Caleb for help.

Sandy solicits help from Trey with the Newport Beach charity yard sale. When one of the auction's most expensive pieces goes missing, Ryan and Seth could also use help.

Marissa hosts a birthday party for Trey that quickly gets out of control. When Summer finds out what Seth's potential graphic novel publisher is really like, Seth is in big trouble.

After the wild party, Sandy, Seth and Ryan plan to save another Atwood from going to jail. Kirsten and Carter take a trip to wine country. Caleb rebuffs Julie's romantic advances.

Visiting Miami Beach, Seth and Ryan meet Mary-Sue, who helps Seth get on the Music Video Nation spring break special. Carter leaves Kirsten alone at the Newport Living offices.

Kirsten has been drinking more than just tomato juice for breakfast. Ryan wonders if something happened between Marissa and Trey. Summer confronts Reed about the graphic novel.

Sandy and Caleb confront Kirsten. Ryan heads home to Chino as he looks for the truth. Summer refuses to let her relationship with Zach and Seth stop her from attending the prom.

In the season finale, Sandy must make a life-changing decision to save his marriage to Kirsten. Seth, Summer, Marissa and Ryan are caught in the crossfire at The Bait Shop.