A NIGHT TO REMEMBER ON "THE O.C." THURSDAY, AUGUST 4, ON FOX

Sandy and Caleb confront Kirsten about her behavior. Ryan, looking for the truth about Trey and Marissa, heads home to Chino. Meanwhile, Summer won't let her three-way relationship with Zach and Seth get in the way of her attending the prom. And Julie and Caleb toast to their final evening together as husband and wife on "The O.Sea" episode of THE O.C Thursday, Aug. 4 (9:00-10:00 PM ET/PT) on FOX. (OC-223) (TV-TBA)

Cast: Peter Gallagher as Sandy Cohen, Benjamin McKenzie as Ryan Atwood, Mischa Barton as Marissa Cooper, Rachel Bilson as Summer, Adam Brody as Seth Cohen, Kelly Rowan as Kirsten Cohen, Melinda Clarke as Julie Cooper, and Alan Dale as Caleb Nichol.

Guest Cast: Michael Cassidy as Zach, Logan Marshall-Green as Trey Atwood, Nikki Griffin as Jess, and Marguerite Moreau as Reed.