To try and improve their chances in the quiz, Professor Muddles presents Keith with his latest invention: the Brain Buster XL, designed to make brains bigger. Professor Muddles decides to test it out on Keith's mug, but instead of growing bigger it shrinks. Later, Keith reveals that he's been trying to fix the Brain Buster XL machine and tests it out on Professor Muddles, who immediately shrinks down to a tiny size and runs all over the desks. Tiny Professor Muddles inspires some answers from Gail and Rapids, but Keith wants his teammate back. On the way back to his desk, tiny Professor Muddles is caught underneath a sun hat, but amazingly Keith manages to save the day.