| Episode cast overview, first billed only: | |||
| Zachary Levi | ... | Chuck Bartowski | |
| Yvonne Strahovski | ... | Sarah Walker | |
| Joshua Gomez | ... | Morgan Grimes | |
| Ryan McPartlin | ... | Devon 'Captain Awesome' Woodcomb (credit only) | |
| Mark Christopher Lawrence | ... | Big Mike | |
| Vik Sahay | ... | Lester Patel | |
| Julia Ling | ... | Anna Wu | |
| Scott Krinsky | ... | Jeff Barnes | |
| Sarah Lancaster | ... | Ellie Bartowski (credit only) | |
| Adam Baldwin | ... | John Casey | |
| Nicole Richie | ... | Heather Chandler | |
| Ben Savage | ... | Mark Ratner | |
| Michael Weaver | ... | Dick Duffy | |
| Bonita Friedericy | ... | General Diane Beckman | |
| Tony Todd | ... | CIA Director Graham | |
Chuck's memory flashes when seeing nerdy engineer Mark Ratner in Buy More, the partner of Sarah's high-school nemesis Heather Chandler. He's suspected of selling secret military technology. So Chuck accompanies Sarah, under her real name Jenny, to their high school-reunion. They and babysitter Casey look for possible buyers, but soon discover Mark is being blackmailed, only it's unclear who the fiends among the (fake?) alumni are. Written by KGF Vissers