The Hex Girls, Velma’s favorite band, come to Crystal Cove to give a concert. However, things go awry when an evil phantom attacks with the intention of permanently taking The Hex Girls out of the music business. Meanwhile, Scooby-Doo and Shaggy are having a fight because of the latter’s prom date with Velma in the last episode. Scooby even goes as far as getting a new best friend: Harry, a ventriloquist dummy. Daphne is captured by the Phantom, which makes Fred realize that he has feelings for her. At the same time, Velma shows a few signs of jealousy toward Scooby-Doo.