Lex, Presley, and Munchy get hired by a fancy French restaurant to be off-the-books rat exterminators. There's a party for the Mayor at the restaurant that's set to start and the kids must quickly and quietly catch a rat.

Munchy is trying out to be the new school mascot, Luna the Tuna! When the girls' former friend Crunchy enrolls in their school, they question his true intentions towards Munchy.