Dennis must escape detention and Bash Street School to make the Beanotown Brawny Bean Race before Walter wins it! With the help of a note placed in his desk, he must sneak past Mrs Creecher and make a run for it - unless the mysterious note-giver stops him first.

Pieface steals Professor Von Screwtop's Pastry-based Intelligent Espionage unit (PIE) after forming a strong bond with the pie-shaped robot. Pieface is dismayed when Walter steals it from him to protect his dad from the embarrassing footage the PIE's memory chip holds.