Harbor School's senior prom brings out the best and the worst in everyone. Taylor (recurring guest star AUTUMN REESER) has a great time, while Summer doesn't enjoy herself with her surprising prom date. Seth and Anna (recurring guest star SAMAIRE ARMSTRONG) come up with a plan to win Summer back for Seth. Meanwhile, Marissa convinces Volchok (recurring guest star CAM GIGANDET) to go to the prom with her, and Ryan brings an unexpected old flame. When one of the girls is elected prom queen, it truly becomes a night to remember. Later, when Taylor's prom funds are discovered to be missing, Ryan returns to his old ways, and prom night turns brutal. LISA TUCKER ("American Idol") guest stars as herself.