This second of the authors' books featuring a young adult Mycroft Holmes and his Trinidadian friend and colleague in detection, Cyrus Douglas, finds the sleuths on the hunt for brutal killers and drug dealers. The novel offers quality writing and excellent characterization. Holmesians will enjoy the backstory of Mycroft and Sherlock's dysfunctional family and the explanation for Mycroft's famous indolence in later life. They will also be amused to see Sherlock Holmes as a rebellious teenager. Cleverly, Dr. Joseph Bell, a real-life professor of medicine with whom Arthur Conan Doyle studied, makes a cameo appearance. Readers of historical mysteries will appreciate the book's portrayal of Victorian England's equivalent of today's opioid epidemic; the brutal life of London's poor, especially the unconscionable exploitation of children; Britain's morally bankrupt policy toward China relating to the opium trade; and the racial, gender and class prejudices of the time. Unfortunately, the book disappointed me with its absence of narrative urgency. Despite the appealing characters and a plot that was filled with incident, I never felt eager to know what would happen next. Holmes aficionados and historical mystery fans will find much to like in this novel, but if you're expecting a page-turner, look elsewhere.