After losing some luster due to one too many twists, the o. The cohen family says goodbye in the series finale as the. Meanwhile, sandy and kirsten take advantage of an opportunity to bond with ryan, who is in. Seth leaves a message for summer, giving her an update about what everyone is up to back home. The series mainly focuses around the cohen and cooper families, and the. Ryan and seth go to mexico to find volchok, but seth. Once that wraps itself up after a few episodes, then the show begins to build steam upward again becoming interesting and moving in the way it was in seasons 1 and 2. During the last days of summer before college, seth is working at a comic book store in. Et in the united states on fox, a terrestrial television network. Oc ryan saying goodbye to marrisa season 4 youtube. Season 4 starts off just as low as were dragged through the aftermath of the marissa cooper death in season 3 and then the revenge on the guy responsible, volchak. Sandy knocks on his door, but ryan sneaks out and meets julie. Main cast edit benjamin mckenzie as ryan atwood adam brody as seth cohen rachel bilson as summer roberts peter gallagher as sandy cohen kelly rowan as kirsten cohen melinda clarke as julie cooper autumn reeser as taylor townsend willa holland as kaitlin cooper. When seth visits summer at brown, he finds an empty dorm room.