Horowitz is the only writer authorized by Doyle's estate to write novels regarding Sherlock Holmes. The two main characters, Frederick Chase and Athelney Jones (seen in Doyle's “The Adventure of the Six Napoleons“) play out the archetypal roles of Holmes and Watson as they trail a criminal who is now in London attempting to take over Moriarty's territory after his supposed death by Holmes in the fight over the Reichenbach Falls. Fun for SH fans.