S2, E12: Sandy tries to make amends with Kirsten for keeping Rebecca's (recurring guest star KIM DELANEY) return a secret by showering his wife with Valentine's Day gifts. Zach (recurring guest star MICHAEL CASSIDY), Summer and Seth drive to San Diego to pitch their comic book idea, and Seth is determined to use the trip to get Summer back. Julie returns from her European vacation and has decided to reconnect with Marissa. Meanwhile, Ryan wants to spend Valentine's Day with Lindsay (recurring guest star SHANNON LUCIO), but her loyalty to Caleb gets in the way.