They both seem to talk with their teeth firmly closed shut and with homosexual lisps, and spend most of their investigation moaning about their "clues". Whenever they are around both they and those around them continuously make innuendos to erections.
They are later also hired to solve the 9/11 conspiracy, for which Cartman has been claiming the Jews, Kyle in particular, are responsible. Once again, the boys appear to be solely concerned with their erections rather than the investigation of the case.
Later, however, when Stan and Kyle meet the Hardly Boys' detective father, Mr. Hardly informs them that the Hardly Boys managed to discover the truth behind both the Urinal Deuce and the 9/11 Conspiracy by "following their clues" to a 9/11 Conspiracy Party, where they were "getting clues every five seconds" and where Frank almost "shot clue goo all over Joe". They discover that 9/11 conspiracy theories are themselves a conspiracy conceived by the government to make themselves look more powerful than they really are.
After the case is solved, the Hardly Boys set out to follow more "clues". Despite being citizens of South Park, the Hardly Boys also have a book series of their adventures that is shown during their introduction montage. The books are written by Fredrick Dickinson.
Hardly Boy Mysteries
- "The Secret of the Lost Tunnel"
- "The Hooded Hawk Mystery"
- "The Clue of the Broken Blade"
- "Mystery of the Spiral Bridge"
- "Mystery of the Urinal Turd"
- "The Case of the World Trade Center Conspiracy"