'We need proper ghosts,' said Ned, 'really scary ones with heads that come off and daggers in their chests!' When Madlyn and her younger brother Rollo arrive at crumbling Clawstone Castle, they can see that emergency action is needed before Clawstone falls down completely. With the help of a team of homeless, scary ghosts -- including a one-eyed skeleton and Brenda the Bloodstained Bride -- they hatch a spooky plan to get the money rolling in. But with a sinister scientist on the loose, money might not be enough to save the mysterious beasts of Clawstone Castle ...