Orphan genius Darius enlists the school tough guy to help uncover who sent a note posing the question 'Who Killed Darius Drake?' This adventure soon becomes entangled with the case of Darius' grandfather being imprisoned for forging evidence in the hunt for a diamond necklace. The arrival of this mystery caper is set to coincide with the Usborne Modern Classics relaunch of Philbrick's "Freak The Mighty".