The princess of Joust for Fun has mysteriously disappeared. To make matters worse, there's a fire-breathing dragon roaming the castle grounds! Has the Black Knight--the ghost of the castle's original owner--returned with his pet dragon to claim his castle and all that lies within? Or is there someone else behind the Black Knight and his dragon--someone who wants to scare everyone away from Joust for Fun and ensure its utter failure? Join Scooby-Doo, Shaggy, Daphne, Fred, and Velma as they explore the castle, and help them solve the mystery of the Phantom of the Knight.