Scooby-Doo and the Spooky Castle Adventure

The town of Crystal Cove and the surrounding areas are being terrorized by monsters and ghosts. The local Baroness Maria Richman has gone missing and it is suspected that the ghost sightings have something to do with it! Tasked with solving the crime, you arrive at the same conclusion as Mystery Inc. Unfortunately when you get to the Spooky Castle, Mystery Inc. gets locked out at the same time you get locked in! You soon realize that Mystery Inc. are able to help by communicating clues via magic portraits inside the castle. Discovering a secret dungeon and monster lab in the castle, you realize this is where the evil is being created and set about solving the crime. You come to the conclusion that the person responsible almost certainly works in the castle - but who could it be as there are several suspects?