Scooby, Shaggy, and the rest of the gang have an encounter with a fireball while driving near an old castle. They decide to investigate the old castle which turns out to be a tourist attrion named Joust For Fun. Once there, they meet Jane McHaggis, the proprietor of the establishment, who explains that the castle is being haunted by the Black Knight. The Black Knight is believed to be the spirit of the original owner of the castle and has kidnapped the ress playing the castles princess. He also has a fire-breathing pet dragon roaming the grounds.