"Mystery of the Urinal Deuce" (Season 10, Episode 9) satirizes the 9/11 Truth movement by comparing a school vandalism investigation to conspiracy theories. The episode concludes that the U.S. government encourages such theories to appear more capable than they actually are, with Stan revealed as the culprit. Detailed plot and script information can be found at South Park Archives . Mystery of the Urinal Deuce | South Park Public Library