In a flashback to the 80s, 17-year-old Lily Rhodes gets kicked out of boarding school and runs away to Los Angeles, reconnecting with her parents, Rick and Cece, and sister, Carol. Back in present day, Blair and Nate attend prom together, but the evening doesn't turn out exactly as planned and Chuck and Serena have a little something to do with that. Serena and Lily don't see eye-to-eye over Serena's recent run-in with the law. No Doubt performs in the flashbacks as an 80s band called "Snowed Out."
Elenco: Blake Lively , Leighton Meester , Penn Badgley , Chace Crawford , Ed Westwick , Kelly Rutherford , Matthew Settle , Kaylee DeFer , Jessica Szohr , Kaylee De Fer , Kelly Rutherford , Kristen Bell , Matthew Settle , Michelle Trachtenberg , Taylor Momsen .