“Colfer’s clever spin-off of the Artemis Fowl series focuses on Artemis Fowl’s twin younger brothers—hyperintelligent Myles and near-feral Beckett, both 11. With their older sibling on Mars, the fraternal twins are dragged into a madcap adventure when they’re kidnapped by Lord Teddy Bleedham-Drye, a 150-year-old duke seeking the secret to immortality, which he believes rests in the venom of a diminutive troll that the twins are protecting. Sister Jeromina, a nun and agent of the secret organization ACRONYM, also has them in her sights. Meanwhile, Lower Elements Police Specialist Lazuli Heitz, a pixel (pixie-elf hybrid), seeks to rescue the imperiled troll—and the twins by extension. A globetrotting caper transpires as the myriad factions attempt to outwit, outsmart, escape, and double-cross one another. Colfer’s trademark tongue-in-cheek narrative voice is on full display, his characters existing in a preposterous balance between sincerity and absurdity, mad science, and technology. Though a working familiarity with the previous books is handy, this series opener is accessible and entertaining: the fast-paced plot, filled with unexpected betrayals, death-defying feats, and secret train cars, will appeal to Fowl readers established and new.”