Kirsten's anxiety over Seth reaches the breaking point; Caleb becomes increasingly paranoid.
The Way We Were
Seth, Ryan, Marissa and Summer adjust to their changing dynamics.
The New Kids on the Block
Summer reconsiders her feelings for Seth as he tries to prove that his friends do not know him as well as they think.
The New Era
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.
The Chrismukkah That Almost Wasn't
During a "Chrismukkah" celebration, secrets come out that may change the Cohen family forever.
The Family Ties
The Cohens decide to try to accept Lindsay as a member of the family after Caleb's revelation.
The Power of Love
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.
The Second Chance
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.
The Lonely Hearts Club
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.
The Father Knows Best
While Rebecca pays her last respects to her father, Kirsten grows impatient with Sandy's long absences from home and pays Rebecca a visit.
The Rainy Day Women
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.
The Blaze of Glory
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.
The Brother's Grimm
When a visitor from Ryan's past comes to town, he is worried that nothing good can come of it.
The Risky Business
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.
The OC Confidential
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.
The Return of the Nana
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.
The Dearly Beloved
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.
The friends worry as the cops want to know who shot Trey.
The Shape of Things to Come
Sandy worries about Kirsten's friend. Marissa gets bad news.
The End of Innocence
Ryan and Marissa enjoy a night to remember.
The Last Waltz
Marissa attends a new school. Seth gets Summer in trouble.
The Perfect Storm
Ryan makes a life-changing decision with Sandy's support.
Taylor ruins Seth's night by keeping Summer away.
The Anger Management
Taylor causes a major rift between Seth and Summer.
The Game Plan
The friends plan their futures. Julie returns to her roots.
Ryan works for Sandy. Johnny tells Marissa how he feels.
The Chrismukkah Bar Mitz-Vahkkah
Kirsten makes amends with Julie. Seth invents a holiday.
The Safe Harbor
The friends try to get Marissa back into their school.
The Sister Act
The clan tries to re-create a perfect East Coast Christmas.
The Pot Stirrer
Kaitlin causes trouble as she celebrates her birthday.
Kirsten and Julie take their matchmaking business too far.
The Heavy Lifting
Tragedy strikes the friends. Johnny's cousin arrives.
The Road Warrior
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.
The Secrets and Lies
Marissa seeks solace with bad boy Volchok and his crew.
The Day After Tomorrow
The kids receive their college acceptance or rejection letters.
The Dawn Patrol
Ryan visits his mom. Julie gives Volchok stern advice.
The College Try
The friends go to college orientations. Seth sees Anna.
The Party Favor
Senior prom brings out the best and the worst in everyone.
The Man of the Year
Marissa visits Kaitlin at boarding school.
The end of senior year brings excitement and drama.
High school seems like a distant memory to the graduates of Harbor School in the ocean-side community of Newport Beach in Orange County, California, because they have been thrust into adulthood after the death of their friend Marissa Cooper.
Ryan travels to Mexico with a stubborn Seth in tow to put an end to his turmoil in the only way he knows how, but he comes up empty in his quest for revenge. Meanwhile, Seth meets some new friends in Mexico.
The Cold Turkey
It's Thanksgiving morning at the Cohen house, and the family is still dealing with what happened in Mexico. Sandy makes a deal to help Volchok but lets Ryan intervene. As Summer packs, she wonders if she can deal with Newport anymore.
When Summer tries to become the gossip-loving girl she once was, she realizes Brown may have changed her forever. Seth continues to be supportive. Ryan empathizes with Taylor and surprisingly helps her out of a bind.
The Sleeping Beauty
Summer and Che take their activism to a new level. After Julie flirts with a hot tennis instructor whom Kaitlin likes, the younger Cooper gets her revenge at a charity party. But later, Kaitlin helps save Julie and Kirsten's dating service.
The Summer Bummer
When Seth visits Summer at Brown, he finds an empty dorm room. Sandy and Kirsten take advantage of an opportunity to bond with Ryan. Kaitlin meets the mean girl of Harbor School and tries to throw a huge party at the Roberts house.
It's time for another Chrismukkah in Orange County. After Ryan and Taylor have an accident while hanging holiday lights, they realize everything is not as it seems, and they must do whatever it takes to make things right again.
The Earth Girls Are Easy
Ryan plans a surprise road trip for Taylor and himself. When Summer confronts Seth about not making plans, Ryan's romantic getaway is spoiled. Summer's future rests in the hands of a character that the gang meets on the way to Las Vegas.
The My Two Dads
Newly engaged Seth and Summer both panic about the prospect of being married, but neither will break it off, despite the advice of their friends. They begin a game of one-upmanship that almost leads them to Las Vegas for a wedding.
The French Connection
Henri-Michel gets too close to home while promoting his memoirs. After Henri-Michel tells Ryan about Taylor's life in France, Ryan questions his relationship. Seth visits Dr. Roberts in Seattle to ask for permission to marry Summer.
The Dream Lover
Che and Seth take a trip to a forest, where Che has a dream and discovers his spirit might be in love with someone unexpected. Afterward, Seth and Summer finally speak for the first time since she rejected his marriage proposal.
The Groundhog Day
As the Cohens prepare for Kirsten's birthday party, Kirsten gets news that will change her life. Julie is having a love affair and Kaitlin is doing everything to stop it. While Ryan acts as if he doesn't miss Taylor, she visits a therapist.
The Case of the Franks
As Valentine's Day approaches, Ryan worries the pressure will ruin his relationship with Taylor. Revelations, along with a psychic's dire predictions, cause Summer and Seth to question whether or not they are destined to be together.
Taylor prepares for her birthday celebration but frets over the fact Ryan has still not told her that he loves her. Even more concerning is that she has applied to and been accepted at Berkeley. And an earthquake shakes Newport Beach.
The Night Moves
In the aftermath of a major earthquake that cuts off power and communication between the Cohens and their loved ones, Seth must take over Ryan's role as the protector when Ryan is injured, and the boys are stranded on a deserted road.
The End's Not Near It's Here
The Coopers and their friends build new lives, resolve lingering issues, face major decisions and undergo shocking personal transformations. No matter what happens, the members of this family know they will always have one another.