S4, E6: When Seth visits Summer at Brown, he finds an empty dorm room. Meanwhile, Sandy and Kirsten take advantage of an opportunity to bond with Ryan, who is in a Taylor-induced haze, Kaitlin meets the mean girl of Harbor School and tries to best her by throwing a huge party at the Roberts house, and Julie learns that Newmatch is more than just a dating service. Elsewhere, the truth about Che comes out.