Trouble is brewing at Blaggard's School for Tomorrow's Tyrants. Sir Byron's Brain, a priceless legendary diamond, has gone missing. If it leaves the school grounds, Blaggard's will be destroyed forever and the head teacher obliterated! Could the evil Brotherhood of Brimstone - an ancient secret society - have anything to do with it? Best friends Milly and Charlie embark on an adventure to find out. They discover a web of evil plots involving Gruffles, Charlie's stinky dog, and Wolfie, the robot dog turned invisible superhero. On top of this, Blaggard's is expecting a school inspection from the mysterious Dr X - Chief Inspector of Criminal Schools. He could turn up at any time, and no one knows what he looks like. Time is running out for Milly and Charlie. Will Dr X appear? And can our heroes defeat the evil Brotherhood, rescue their canine companions and save the day? The rollicking second instalment in Kate Wiseman's Gangster School series.