Jason Mraz (Dion) and Fefe Dobson (Tina Turner) are the guest impersonators on Bandstand, where Roxanne wants a hairstyling job. She also has boy woes: Lenny's return has clearly rattled Luke. Meanwhile, Beth makes a decision about her pregnancy; Nathan (Keith Robinson) is drafted, and Sam tries to get Meg to talk to Drew about his CO status; JJ's unit goes on a mission with a by-the-book new corporal (John Sloan); Jack considers his political options over coffee with Will's former teacher, the former Sister Grace (Robyn Lively); Will might be made to repeat fourth grade; and Patty uses hamster chips to get closer to Carl (Wes Robinson).