First-time novelist Sands has written an exciting and self-assured tale of alchemy and dark secrets set during the late-17th-century reign of King Charles II. Fourteen-year-old orphan Christopher Rowe is lucky to be apprenticed to a kindly apothecary, Master Benedict Blackthorn. But someone—the Cult of the Archangel, it is rumored—is murdering London’s apothecaries, believing that members of the Apothecary’s Guild are concealing a dangerous secret. Christopher is an easygoing boy, fond of pranks and experiments (the book opens with his ill-advised and ill-fated attempt at mixing up some gunpowder), but after Master Benedict is assaulted, he finds himself on the run, pursued by the murderous henchmen of a rival apothecary and the dangerous Lord Richard Ashcombe, His Majesty’s Warden. Sands adeptly balances the novel’s darker turns with moments of levity and humor, and fills the book with nicely detailed characters and historical background—plus lots of explosions. It’s a story that should have broad appeal, while especially intriguing readers with an existing interest in chemistry, history, and decoding puzzles. Ages 10–14.