Fourteen-year-old Jack Mason, orphaned by a tragic tightrope-walking accident, is plucked out of an orphanage by "consulting detective" Ignatius Doyle. Their first case together quickly progresses from tracking a missing person to fielding run-ins with the Darwinist League, Nazis, and the mysterious "M," who wants diamonds in exchange for returning an atomic bomb. First-time author Pitt has crafted a steampunk homage to Sherlock Holmes, complete with references to Sir Arthur Conan Doyle's fictional characters, as well as references to actual WWII-era figures. At times, the audience for the book is called into question by awkward exclamations ("Bazookas!"), in-text explanations for concepts and historical plot points, and characters who act well beyond their years, but lots of action and the game of unveiling all the allusions keep things moving. An author's note would have been helpful for historical context; consider pairing with nonfiction, such as Sarah Ridley's Winston Churchill and World War II (2013), for STEM connections. An engaging series starter.