is on a stage talking about how the town was once saved by Friar Serra and his donkey Porto. Doogle McGuiness is there to play the Friar in the play. As the director introduces the concept of the play, he shows how they have a box with the original Friar in it. The Friar apparently comes to life and attacks them.
The next night, Daphne, along with Shaggy and Scooby, help sneak Fred and Nova in her house. While they're doing that, Shaggy recieves a text from Van Ghoul who laments the destruction of the play and talks them into helping. They meet George Avocados who now has to work as a janitor.
Pericles talks to Brad and Judy and tells them they must get the disk back from the gang.
Van Ghoul talks to the gang and convinces them to do the play in the absence of the intended cast. Velma goes off to research Friar Serra and runs into his mummy. Velma runs away from it and almost gets caught when the mummy grabs her. Van Ghoul talks to the mayor who tells him that Valdesh Helgenjew will be here to see the play. The gang looks around for clues and finds a trail of some sort of material in the basement and runs into Doogle who warns them away. They then see the mummy again who warns them not to tell the story because it might awaken Nibiru. The gang prepares for the play anyway and they put on the play as scheduled. The mummy appears and chases Shaggy. After the chase, they find out it was Avocados who was trying to find a diamond once stolen by his father. They then find out Avocados was the SECOND mummy of Serra.
The gang returns to the basement after the play to find the mummy of Serra waiting for them. This time the Mummy comes to life and tells them the truth of how the old Crystal Cove sank into the sea. It was his donkey Porto who did it. When Serra's group had encountered the conquistador, he told them about the curse and left behind two disk peices before running away. Serra's mystery solving group tried to figure out the mystery of what the disk was but became obsessed with it instead of solving the mystery. Eventually the dark power of the disk caused Porto to go mad and set explosive charges that caused part of the town to sink into the sea. Porto was eaten by alligators when he tried to leave town with one of the disk pieces. Serra issues one last warning before crumbling to dust: The only way to stop Nibiru is for Scooby to die!