The cheerleader squad is on a bus (driven by Mr. Barkin) to an event, when Ron suddenly becomes agitated at the sight of a "too familiar" place. He becomes even more upset when Kim shows him their current location on the Kimmunicator, announcing that it's his "worst nightmare -- return to Camp Wannaweep".
The bus then hits a nail board, flattening the tires and forcing it to stop. Everyone takes shelter in the abandoned campground, while Ron recounts [[SummerCampy the awful summer he spent there as a child]]. Among other things, he was bullied by another camper named Gil, who spent most of his time swimming in the lake (which Ron avoided because it looked and smelled dubious).
Meanwhile, a [[FishPeople creature resembling a giant humanoid frog]] is lurking and watching, finally moving in to attack. It turns out to be Gil, mutated by the polluted water of Camp Wannaweep and determined to get revenge on [[NeverMyFault the one he blames]] for his condition: Ron Stoppable.
!!This episode provides examples of:
* AllUpToYou: Gil traps Kim, Mr. Barkin, and the cheerleaders with his slime, leaving it up to Ron and Rufus to capture him and save the day.
* FishPeople: Gil.
* SummerCampy: Ron has ''very'' bad memories of Camp Wannaweep.
* ThatManIsDead: Played for laughs -- Gil declares that he is no longer "Gil" but "Gill" with an added "L".