It's New Year's Eve in the O.C. and to celebrate the holiday, Ryan puts together a road trip as a surprise for Taylor, but his surprise is spoiled when Summer finds out that Seth hasn't planned anything for her. Later, the four head to Las Vegas where they meet a raver who may be able to help Summer's future. Back in Newport, the Bullit has a friend look into Julie's accounting.

Eddie and Joys daughter, Allison (guest star Krysten Ritter), comes home for the holidays to celebrate New Years with her parents. When she gets some bad news from her boyfriend, Allison turns to her mother for help, leaving a snubbed Eddie perplexed. At the Woodcocks New Year's Eve party, Eddie lightens up his mood to impress his daughter, but as the clock strikes midnight and a new year begins, Allison realizes she likes her "big, dark, angry, wonderful dad" just the way he is.

Aiden's under pressure from Madison, Kyla, Ashley and Spencer over friendship and relationship issues. It seems that in order to make one of them happy, he has to break another one's heart

Arthur and Paula Carlin revel in the prom excitement as their kids prepare for their next high school milestone. Clay and Chelsea cherish their last moments of teenage freedom and Glen drops a bomb with the announcement of his unexpected career path. But the evening's festivities are cut short when Aiden reveals his not-so-secret secret that changes his relationships with his female friends forever.

Stephen Fry, Alan Davies and guests discuss quite interesting topics beginning with 'D' in this Christmas special.