A third mystery for thirteen-year-old Agatha Oddly - a bold, determined heroine, and the star of this stylish new detective series. Agatha Oddlow is on the case with yet another adventure! An assistant at the National Gallery has gone missing, but when Agatha begins investigating, she uncovers a plot bigger than she could ever have imagined. Join Agatha as she travels throughout London and into the very heart of the mystery...