The O.C.

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.

Public school? No problem. Marissa's glad to be at a school where no one knows about her. Oops. Everyone knows. Charlotte closes in on Kirsten. And Summer spies on someone lip-locked with Taylor.

Is Ryan shipping out? Sandy's mind-meld persuasion skills fail to convince him to stay. But where there's a will, there's another Cohen way. Charlotte now zeroes in on Julie; Summer outwits Taylor.

Party by night. Surf by first light. The Dawn Patrol beach blast is the backdrop for a developing Marissa-Johnny attraction. Meanwhile, Taylor has a crush on...Seth?! And Ryan again lets his fists do the talking.

Charlotte and Julie throw a faux-benefit. Taylor causes a rift between Seth and Summer. The tension between Ryan and Volchok comes to a head.

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?

Marissa cares for an injured Johnny. But are they getting too close? Seth becomes insecure when Summer gets a higher score than him on the SATs.

Ryan, Marissa, Seth, and Summer raise money for Johnny's surgery by throwing Ryan a Bar Mitzvah.

Ryan, Seth, and Summer plot to get Marissa back into Harbor School.

Marissa's sister returns home from boarding school with secrets, lies, and a bag of stolen cash. Veronica and Julie compete for the affections of Niel Roberts. Johnny tries to distance himself from Marissa.

Julie throws Kaitlyn a birthday bash. Sandy tries to close a deal. Marissa butts heats with her sister. Seth spirals after being offered a college interview.

The Johnny-Kaitlin-Marissa-Ryan situation finds closure, perhaps, and tragedy for sure. Summer may be running out of forgiveness for Seth's half-truths. And Dr. Roberts makes a startling admission to Julie.

Kirsten and Julie throw a Valentine's Day party, as the community mourns the loss of Johnny.

Ryan and Sadie go on a road trip to look for Johnny's dad. A concerned Summer finds out about her dad's relationship with Julie. The police suspect foul play in Johnny's death. Marissa runs into Volchok.

The Cohens throw Ryan a party for his eighteenth birthday. Ryan can't decide whether or not to invite Marissa. Sandy tries to track down Dawn. Summer confronts Julie. Marissa crashes into an old memory.

Jess returns with news about Trey. Kirsten helps Ryan confront his savior complex. Seth and Summer receive sex counseling from Taylor.

Marissa's ties with Volchok send her into a substance abuse downward spiral. Summer is concerned about her friend--and the fate of her father's relationship if things don't improve. Ryan and Sadie's relationship is on the line, as Ryan and Marissa keep finding themselves intertwined in one another's lives. Seth spends some quality time with Kirsten, as she reaches nine months sober. The events at Newport Group turn violent.

College acceptance letters arrive. Three get in... and one doesn't.

Ryan heads to Albuquerque to invite his mom to graduation, while Summer tries to figure out why Seth broke up with her.

Ryan and Marissa arrive at Berkeley, and Summer and student/poseur Seth visit Brown for freshman orientation weekends. Familiar faces surface.

Harbor's Senior Prom brings out the best and the worst in everyone.

Sandy is voted Man of the Year. Kirsten hits the bottle. Summer tries to write an impulsive wrong. Ryan is blackmailed into stealing a car. Seth burns down his dad's office. Marissa gets Kaitlyn out of trouble.

On graduation day, Marissa is leaving to be with her dad, but Volchok has feelings for her and is angry at Ryan.