Cartman is convinced that there is a conspiracy behind the September 11th terrorist attacks, so he sets off to find the real culprit. Meanwhile, Mr. Mackey is wondering who went number 2 in the urinal of the men’s restroom. In order to get to the bottom of this, Mr. Mackey puts the Hardly Boys on the case. As it turns out, these two seemingly unrelated mysteries have intrinsic connections, all pointing to governmental involvement.