In the episode "Small World," Fix and Foxi go to Professor Knox's lab and, out of curiosity, try a drink from a beaker. Unbeknownst to them, the concoction is an experimental shrinking potion. After drinking it, they immediately begin to shrink down to a minuscule size, and the world around them becomes gigantic and dangerous. The boys then have to navigate through the enormous lab to find the antidote to restore their sizes.