'We shall be detectives, Sponge!' exclaimed Mildew. 'We shall solve the Mystery of the School Spoon!' Mildew and Sponge don't think much of Maudlin Towers, the blackened, gloom-laden, gargoyle-infested monstrosity that is their school.

But when somebody steals the School Spoon and the teachers threaten to cancel the Christmas holidays until the culprit is found, our heroes must spring into action and solve the crime!

But what starts out as a classic bit of detectivating quickly becomes weirder than they could have imagined.

Who is the ghost in the attic? What's their history teacher doing with a time machine? And why do a crazy bunch of Vikings seem to think Mildew is a werewolf?