Ryan and Marissa begin their life together as "friends", but both discover that it might be harder to do than to say. Theresa drops into Newport for work, and another visit. Julie and Luke realize the meaning of "booty calls", and Seth and Summer make a declaration.

Anna announces that she is leaving Newport to go back to Pittsburgh, which leaves Seth feeling saddened and guilt-ridden. Legal troubles brew for Caleb and Kirsten while Sandy works to solve them. Luke and Julie's secret romance is getting harder to contain, and Theresa brings a bit of trouble from Chino to the O.C.

Nana Cohen comes to California for Passover with some sad news. Ryan searches for Marissa, who'd gone missing after learning Julie and Luke's secret, and he finds her in the most unlikely of places. Summer tries to impress Nana. Jimmy and Hailey take a step forward.