JD Pardo

Julie and Dr. Roberts (recurring guest star MICHAEL NOURI) announce their engagement, and the Cooper ladies move in with Summer and her dad. Meanwhile, Marissa drifts away from Summer and the group when she seeks solace in the company of bad boy Volchok (recurring guest star CAM GIGANDET) and his crew. Ryan tries to move on with Sadie (recurring guest star NIKKI REED), but Seth's concern for Marissa gets in the way. At the Newport Group, Sandy's woes with Matt (recurring guest star JEFF HEPHNER) continue. And Kirsten surprises Seth with a night out.

Ryan struggles with the decision of whether or not to invite Marissa to his birthday party, and Sandy wants to include one of Ryan's relatives in the celebration. Meanwhile, Julie and Dr. Roberts (recurring guest star MICHAEL NOURI) come clean with Summer and Marissa. Also, Ryan and Sadie (recurring guest star NIKKI REED), along with fellow new couple Marissa and Volchok (recurring guest star CAM GIGANDET), grow closer.

Ryan leaves Newport to visit his mom, but before they meet, he has a steamy encounter with her co-worker. Meanwhile, Seth is keeping secrets, and Taylor (recurring guest star AUTUMN REESER) and Summer devise a foolproof plan to figure out what's going on with him. When their plan backfires, Summer is devastated. Julie Cooper visits a surprised Volchok (recurring guest star CAM GIGANDET) and gives him some stern advice. Later, Marissa confronts Volchok's friends and saves a girl from an intense situation at a raging party. Meanwhile, Sandy puts an end to the trouble with Matt (recurring guest star JEFF HEPHNER) but leaves Kirsten at home alone.

When parents accuse Veronica of providing a fake ID to their son, who's now in an alcohol-induced coma, and files suit, the search to find who's responsible leads Veronica to a clandestine, exclusive organization operating on Neptune High's campus with a possible connection to Duncan. Meanwhile, Aaron Echolls (recurring guest star HARRY HAMLIN) hires Keith to find out who's supplying pictures to the tabloids that humiliate his wife, Lynn (recurring guest star LISA RINNA). Later, Veronica hides an electronic device in the office of guidance counselor Rebecca James (recurring guest star PAULA MARSHALL) to eavesdrop on grief counseling sessions and learns some surprising information about her friends.