The gang is called in to rid the local museum of some ghost knights who are scaring away all the toursts. The museum director tells the gang that the last curator quit because of the ghosts, while working late. It will take a whole lot of accidental messing up in the armor room, and a big accidental sneeze by Scooby-Doo, and a huge accidental crash in the Egyptian room, before the gang gets to the bottom of this mystery.
He supposedly quit because of the ghost knights as well as everyone else. Was suspiciously spying on the gang from around the corner as they looked for clues in the armor room.
Gracen, using a secret hologram switch box hidden in the Egyptain room to activate holograms of the Ghost Knights.
He had found the treasure hidden in the Egyptian Room, and he was trying to get the map to it out of the coffin in that room.
An enigma can be found in Darryl Taylor's and Kravitz Doth's musuem piece. The story's short, and the identity of the villain isn't a mystery, but Taylor's and Doth's characterization of Mystery Inc. gives the short its punch. Robert Pope and Scott McCrae are on hand to keep everyone on their best artistic behavior and add detail to Egyptian backdrops as well as technological spookery.