En route to the Montreal Rock Festival, the gang runs into Simple Plan. As both their vans are wrecked, they have to spend the night at a nearby ghost town. It soon becomes obvious that something invisible is out to get Simple Plan, and even worse for Velma, Gibby Norton is also present in the ghost town.
This episode contains examples of the following:
- Anti-Sneeze Finger: A fallen pepper shaker causes pepper to fall on Scooby's nose. After Shaggy uses this technique on him, Scooby promptly sneezes anyway... and blows the villain across the room. This proves beneficial, as said villain was about to hit the pair with a jukebox, and the sneeze results in him being flattened by it.
- As Himself: The members of Simple Plan - Pierre, Jeff, David, Sebastien and Chuck - appear as themselves.
- Cowardly Lion: Even though Scooby is scared of the Invisible Madman and spends much of the episode running, he attacks him and drives him off when the villain knocks Fred unconscious.
- Creator Cameo: Simple Plan perform the What's New, Scooby-Doo? theme song.
- Dramatic Irony: Played for Laughs; one of Simple Plan's musicians says he doesn't feel frightened because Scooby is on their team, saying that probably nothing could scare the "big strong dog". Fred, Daphne and Velma chuckle.
- Dreadful Musician: It's revealed the suspects all had their own band and came up the scheme so they can replace Simple Plan at the festival. Given their music playing, it's easy to see why.
- Dude, Not Funny!: When Pierre realises that he's the only member of the band who hasn't been abducted, Daphne suggests a solo career. He responds with a Death Glare.
- Even the Dog Is Ashamed: The suspects' rock-and-roll band playing is so awful that Scooby burrows into the snow to hide from it.
- Everybody Did It: Unusually for the franchise, all the suspects were in on the plan this time around.
- Invisible Jerkass: The titular Invisible Madman has this as his gimmick, naturally — as a man in a specially designed suit.
- Mythology Gag: The episode pays homage to The New Scooby-Doo Movies, where celebrity guest stars in animated form helped the gang solve cases.
