The O.C.

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

Seth, Ryan, Marissa and Summer adjust to their changing dynamics.

Summer reconsiders her feelings for Seth as he tries to prove that his friends do not know him as well as they think.

Seth and Sandy take the rest of the family along for the ride as they embark on new adventures.

Seth, Ryan, Summer and Marissa attend the SnO.C. Winter Ball. Julie and Jimmy spend time together.

During a "Chrismukkah" celebration, secrets come out that may change the Cohen family forever.

The Cohens decide to try to accept Lindsay as a member of the family after Caleb's revelation.

After Caleb's revelation, Lindsay and Ryan try to figure out their exact relationship.

Marissa, Summer and Lindsay have a girls' night out while Ryan, Seth and Zach stay in and bond over video games and pizza.

Zach and Seth start a comic book based on their lives in Newport Beach. Sandy decides to help an old friend find his daughter, but the search leads to more questions.

Summer decides to take an active role in the making of the comic book, but Seth isn't sure he can handle spending that much time alone with her.

Sandy showers Kirsten with valentines to make up for keeping Rebecca's return a secret. Zach, Summer and Seth head to San Diego to pitch their comic-book idea, and Seth plans to use the trip to get Summer back.

While Rebecca pays her last respects to her father, Kirsten grows impatient with Sandy's long absences from home and pays Rebecca a visit.

Summer and Seth share a kiss when she leaves Zach at the airport. Ryan is surprised when Lindsay makes a difficult choice. Marissa's relationship changes course in an unexpected way.

Ryan and Caleb are confused by Lindsay's actions. Marissa takes a break to join Summer, Seth and Ryan at the mall. Julie and Kirsten await the arrival of the new editor of Newport Living.

Seth is determined to bring back the spirit and fun times of last year, but Alex's growing jealousy over Marissa may ruin his efforts.

When a visitor from Ryan's past comes to town, he is worried that nothing good can come of it.

When Sandy becomes the honoree chair of the Newport Beach charity yard sale, he gets help from Trey, who has his first run-in with the Newpsies.

Marissa throws a birthday party for Trey at Caleb's mansion, hoping to help the two forge a relationship. Summer discovers Reed's true identity, leaving Seth in hot water.

Sandy and the boys devise a plan to save another Atwood from jail. Kirsten and Carter take a trip to wine country to fulfill their editorial duties. Caleb returns from Europe and appears immune to Julie's advances.

Sandy, Seth and Ryan travel to South Beach to visit Nana at Leisure World, where they meet a woman who helps Seth take center stage on a music channel's spring break show.

Sandy questions Kirsten about her drinking. Ryan wonders whether something happened between Marissa and Trey. Summer confronts Reed about the graphic novel and finds herself center stage at the launch party.

Filmmaker George Lucas expresses interest in Seth's graphic novel. Sandy and Caleb confront Kirsten about her behavior. Looking for the truth about Trey and Marissa, Ryan heads home to Chino.

Sandy must make a life-changing decision in order to save his and Kirsten's marriage. Seth, Summer, Marissa and Ryan get caught in the crossfire at the Bait Shop.