A troubled teen boy's life is forever changed when, upon landing in jail for a crime his brother committed, a public defender from Orange County, California decides to take him into his home.

Ryan decides to run away from Newport before he can be put into foster care. Seth and Marissa help him find a place to stay without being found.

Ryan's mother arrives in Newport.

It's the annual Cotillon Ball. Ryan continues to pursue Marissa, Seth makes friends with a newcomer, and Jimmy finds himself in hot water.

Ryan takes a job at the Crab Shack diner where a co-worker, named Donnie, might mean bad news for the Newport kids when he takes Ryan and Seth out to party queen Holly Fischer's parties where drugs and alcohol flow freely. Ryan asks Marissa out on a date, and when Luke again tries to intervene, Donnie decides to take matters in his own hands when he tries to starve off Luke... with a gun. Meanwhile, Sandy attempts to help Jimmy sort out his life, and gives him some bad news that be may go to jail for his unauthorized loans to cover his tracks. Also, Julie reveals a long-held secret to Kirsten about her past.

On his birthday, Kirsten's father pays a visit to Newport with his 24-year-old girlfriend, but things get messy when the girlfriend makes advances towards Ryan.

Ryan, Seth, Marissa, and Summer plan a trip to Tijuana. The trip descends into chaos when secrets are revealed and lives are put on the line.

It can't stay in Mexico. Not after heartbroken Marissa took all those pills. And not with Marissa's mom trying to have her institutionalized - something Ryan, Seth, Summer and Marissa don't want to happen.

Calculus. AP English. History. The ways of the human heart. Not everything learned at Harbor High is on the schedule of classes. The Cohen casa is a house divided when Sandy takes an environmental case against Kirsten's father.

Work keeps Sandy and Kirsten apart, Rachel makes a play for Sandy, Julie's secret lover is revealed and - omigod! - Summer realizes she likes Seth (but don't ever tell anyone).

Thanksgiving dinner at the Cohens descends into bedlam when unexpected guests arrive. Ryan returns to his hometown when his brother calls on him for a favor.

No one was supposed to see what happened. But Luke did. And so did Ryan. Now, somehow, all Newport knows that Luke's dad has been living a lie. And subsequent gossip raises questions of secrecy and trust.

Ryan is introduced to a Cohen family tradition as unpleasant memories of the holidays back home resurface. Marissa sinks deeper into depression.

It's New Year's Eve. Ryan may have competition for Marissa's affections. Kirsten's sister stirs up trouble.

Ryan doesn't know much about Oliver, Marissa's therapy friend, but he knows he doesn't like him. Yet, Ryan still assists Oliver when he runs into trouble with the law at a Rooney concert.

He says he's a friend. But who can believe a word Oliver says? During a group getaway in Palm Springs, Ryan is sure he's wise to Oliver's game. Marissa is just as sure Oliver is a friend who needs help.

People who won't be on each other's Christmas-card list: Ryan and Oliver. Their rivalry for Marissa intensifies, with Ryan risking his standing at Harbor to unmask Oliver's true character.

Now sure of the truth, Ryan races against time to keep Oliver from hurting himself or Marissa.

On Valentine's Day, everyone is preparing for the Valentine's singles benefit dance. Luke has a new crush: that being Marissa's mother Julie. Meanwhile, Sandy gives Seth some sex advice over his dating of Summer. Theresa Diaz, an old friend Ryan's, shows up in town as part of the catering services for the benefit, which forces Marissa to lay her feelings on the table that her breakup with Ryan may have been a mistake. Also, Seth and Summer take their friendship to another level.

The Ryan-Marissa thing is more iffy than ever when Theresa hangs in Newport. The telenovela-like suds-o-rama overflows with the Seth-Summer follies, the Luke-Julie fling and an insider who may be a threat to the Caleb-Kirsten biz.

Anna is leaving. Theresa is staying. Seth thinks he's the reason for Anna's planned return to Pittsburgh. And Ryan knows he's why Theresa is staying. But what is either guy going to do about it? Caleb is Riviera's Man of the Year (uh-oh).

Operation Protect Marissa! Seth and Ryan plan to keep Marissa from finding out about her mom's affair. It also becomes Operation Rescue Hailey when they inadvertently attend a Hollywood party where she's a stripper.

Marissa runs away after learning a heartbreaking truth, to a place where only Ryan could find her. Sandy's mother visits for Passover.

Engagement announcements are joyful news, right? Not when it means the one person Kirsten despises will become her stepmom. And not when Marissa will have a new family arrangement she doesn't want.

Julie's wedding shower is anything but uneventful. Seth has lunch with Summer's dad.

The Cohen men, along with Ryan and Caleb set out to Las Vegas for a bachelor party. Meanwhile, the girls are having fun with their own adventures.

On Julie and Caleb's big day, Ryan may be leaving Newport forever. Everyone handles it differently.

It's been three months since Ryan left to live with the pregnant Theresa in Chino, and Seth subsequently sailed off to Portland to live with Luke and his divorced, gay father. With one week before school will start, Kirsten is furious that Sandy has yet to bring Seth back to Newport. Sandy says that they can't bring him back kicking and screaming, because that will only make him want to run away again. Also in the Cohen household, there's a group of re-modelers led by macho man Archie, creating a new family room and re-designed kitchen, a project that apparently was used to distract Kirsten from going from having two sons in the house, to none. Meanwhile, Summer tells Marissa that she's been hanging out with a new kid, but refuses to get close to him, saying she'll never get close to a boy again. Marissa knows just how she feels. She misses Ryan but just can't bring herself to call him to see how he's doing. Caleb's paranoia about being indicted is growing all summer long. Back at the Cohen household, Kirsten calls Seth in Portland and begs him to come home. Seth refuses, saying Newport is an awful place. Sandy decides to fly to Portland to possibly use reverse psychology to convince Seth to come home. He also visits Ryan in Chino to deliver him a plane ticket to Portland, thinking maybe the two could deliver an unbeatable one-two punch combination. It's apparent to everyone in Chino, including Theresa, that Ryan is miserable, and doesn't consider it to be his home anymore. Before heading up to Portland, Sandy speaks with Caleb in a parking garage, as Cal is paranoid his home, the office, and other places might be bugged and the phone lines tapped. Once in Portland, Sandy is shocked to see the level of hostility Seth shows his father. Seth seems content to stay in Portland, and continuing to resent his parents for letting Ryan go, and Ryan for leaving. Back in Newport, Jimmy and Marissa join Kirsten for dinner to keep her company, and Marissa goes into the pool house further fueling her missing Ryan. Sitting on the beach that night, she calls Ryan in Chino, but can't bring herself to say anything, so he lays there listening to her breathe, knowing it's her. Julie tells Marissa she's grounded because she's sick of being ignored. Marissa has a meltdown screaming, crying, and throwing lawn furniture into the pool unable to stand anymore of her evil mother or her evil stepfather. Summer visits the Cohen household with a box of Seth's stuff, telling Kirsten she's there to get rid of anything that ever reminded her of Seth. She dumps the box on the bed, and leaves. Later, just before Sandy leaves Portland he tells Seth that he's fine with him staying in Portland, as long as he knows he's safe and happy. As Sandy is leaving, Ryan is showing up, making his best attempt to convince Seth to go back. It doesn't seem to work until Theresa calls Ryan at Luke's house, and tells him she's lost the baby, saying the doctor couldn't find a heartbeat. Theresa's mother later reveals that Theresa was lying, and she never lost the baby. It's the next morning as Ryan is to leave that the two, Seth and Ryan, decide maybe going back to Newport would be the best thing for the both of them-and the two return to the Cohen household.

The boys are back. Every status is quo. Except: Summer won't kiss and make up. Ryan catches Marissa in a clinch, the DA busts Caleb, Hailey bails and the re-modelers are like a wrecking crew. Home sweet chaos.

Seth pulls off a magnanimous gesture for Summer, then blows it. Lindsay and Ryan become Physics lab partners and share some romantic chemistry. Embattled Caleb names Julie as Newport Group's CE-uh-O.

It's not a date, it's a group hang. So Seth goes with Lindsay, but looks for Summer. Ryan goes with Alex, but would rather be with Lindsay. And Alex...well, stay tuned. That new CEO has a style all her own.

The winter dance is near and a Ryan-Lindsay hook-up is off, on, off, on, off like a light switch. But all will be smoothed over by the time of the big Newport social event. Or not. Plus: Caleb's secret revealed.

Friends, festivities, eight days of gifts, another day with a whole lot of gifts. Seth's formula for the perfect Chrismukkah may come undone when Caleb's confession rocks the Cohen world.

Time to move on: Jimmy decides to relocate to Maui. Time to make a move: Ryan and Lindsay wonder about a first kiss. Time to bust a move: Seth turns bad boy in an attempt to impress Alex.

Familiar faces show up for a final farewell to Caleb. Meanwhile, Sandy takes action to help Kirsten. And when Ryan learns about the Trey-Marissa incident, a showdown - if not a tragedy - is inevitable.

Ryan and Marissa deal with the aftermath of Trey's shooting. Kirsten meets Charlotte at rehab.

The new dean of Harbor School wants to expel Ryan and Marissa. Summer fights with Taylor over being Social Chair. Kirsten worries about leaving rehab.

Caleb's will is read. Ryan and Marissa are told to stay apart.

College applications are due, and everyone has to make up their minds about where to apply. But will their relationships survive this next chapter of their lives?

In a parallel universe, Sandy is married to Julie, Kirsten is Mrs. Jimmy Cooper, Summer is engaged to Ches, and Seth is in full geek mode. And Ryan and Taylor, stuck there after a fall, must change it.

The Cohen men, along with Ryan and Caleb set out to Las Vegas for a bachelor party. Meanwhile, the girls are having fun with their own adventures.

Time to move on: Jimmy decides to relocate to Maui. Time to make a move: Ryan and Lindsay wonder about a first kiss. Time to bust a move: Seth turns bad boy in an attempt to impress Alex.

Operation Protect Marissa! Seth and Ryan plan to keep Marissa from finding out about her mom's affair. It also becomes Operation Rescue Hailey when they inadvertently attend a Hollywood party where she's a stripper.

A troubled teen boy's life is forever changed when, upon landing in jail for a crime his brother committed, a public defender from Orange County, California decides to take him into his home.

Seth pulls off a magnanimous gesture for Summer, then blows it. Lindsay and Ryan become Physics lab partners and share some romantic chemistry. Embattled Caleb names Julie as Newport Group's CE-uh-O.

Engagement announcements are joyful news, right? Not when it means the one person Kirsten despises will become her stepmom. And not when Marissa will have a new family arrangement she doesn't want.

Julie's wedding shower is anything but uneventful. Seth has lunch with Summer's dad.

On Julie and Caleb's big day, Ryan may be leaving Newport forever. Everyone handles it differently.

It's been three months since Ryan left to live with the pregnant Theresa in Chino, and Seth subsequently sailed off to Portland to live with Luke and his divorced, gay father. With one week before school will start, Kirsten is furious that Sandy has yet to bring Seth back to Newport. Sandy says that they can't bring him back kicking and screaming, because that will only make him want to run away again. Also in the Cohen household, there's a group of re-modelers led by macho man Archie, creating a new family room and re-designed kitchen, a project that apparently was used to distract Kirsten from going from having two sons in the house, to none. Meanwhile, Summer tells Marissa that she's been hanging out with a new kid, but refuses to get close to him, saying she'll never get close to a boy again. Marissa knows just how she feels. She misses Ryan but just can't bring herself to call him to see how he's doing. Caleb's paranoia about being indicted is growing all summer long. Back at the Cohen household, Kirsten calls Seth in Portland and begs him to come home. Seth refuses, saying Newport is an awful place. Sandy decides to fly to Portland to possibly use reverse psychology to convince Seth to come home. He also visits Ryan in Chino to deliver him a plane ticket to Portland, thinking maybe the two could deliver an unbeatable one-two punch combination. It's apparent to everyone in Chino, including Theresa, that Ryan is miserable, and doesn't consider it to be his home anymore. Before heading up to Portland, Sandy speaks with Caleb in a parking garage, as Cal is paranoid his home, the office, and other places might be bugged and the phone lines tapped. Once in Portland, Sandy is shocked to see the level of hostility Seth shows his father. Seth seems content to stay in Portland, and continuing to resent his parents for letting Ryan go, and Ryan for leaving. Back in Newport, Jimmy and Marissa join Kirsten for dinner to keep her company, and Marissa goes into the pool house further fueling her missing Ryan. Sitting on the beach that night, she calls Ryan in Chino, but can't bring herself to say anything, so he lays there listening to her breathe, knowing it's her. Julie tells Marissa she's grounded because she's sick of being ignored. Marissa has a meltdown screaming, crying, and throwing lawn furniture into the pool unable to stand anymore of her evil mother or her evil stepfather. Summer visits the Cohen household with a box of Seth's stuff, telling Kirsten she's there to get rid of anything that ever reminded her of Seth. She dumps the box on the bed, and leaves. Later, just before Sandy leaves Portland he tells Seth that he's fine with him staying in Portland, as long as he knows he's safe and happy. As Sandy is leaving, Ryan is showing up, making his best attempt to convince Seth to go back. It doesn't seem to work until Theresa calls Ryan at Luke's house, and tells him she's lost the baby, saying the doctor couldn't find a heartbeat. Theresa's mother later reveals that Theresa was lying, and she never lost the baby. It's the next morning as Ryan is to leave that the two, Seth and Ryan, decide maybe going back to Newport would be the best thing for the both of them-and the two return to the Cohen household.

The boys are back. Every status is quo. Except: Summer won't kiss and make up. Ryan catches Marissa in a clinch, the DA busts Caleb, Hailey bails and the re-modelers are like a wrecking crew. Home sweet chaos.