CAT FIGHT—NICOLE RICHIE (“THE SIMPLE LIFE”) AND BEN SAVAGE (“BOY MEETS WORLD”) GUEST STAR—Chuck (Zachary Levi) learns more about Sarah’s (Yvonne Strahovski) past when they run into her old high school nemesis Heather Chandler (guest star Nicole Richie). Sarah’s teenage insecurities come to surface and she tries to avoid Heather at all costs. Chuck, on the other hand, does everything he can to hear more about Sarah’s hidden life. When Heather’s nerdy husband Mark (Ben Savage) turns out to be a key player in a new mission, the agents must attend Sarah’s high school reunion to prevent the sale of potentially dangerous super-bomber plans — all the action ends with the ultimate cat fight. Meanwhile, Big Mike (Mark Christopher Lawrence) leaves town for a day and Buy More’s new assistant manager Lester (Vik Sahay) decides to implement a new sales policy. Adam Baldwin, Joshua Gomez, Scott Krinsky and Julia Ling also star.