Simon is ecstatic when he's elected as the school's safety monitor. But when Alvin goofs off at school, Simon faces a moral dilemma, and has to choose between doing the right thing or giving Alvin detention and ruining the family vacation.

Theodore is desperate to land the part of the monster in the school play, so Alvin decides to show Theodore how to really scare people. But Alvin scares him so badly, that poor Theodore freezes like a statue. Can Alvin and Simon unfreeze Theodore before the big audition?