London, 1668. The monarchy has been restored-but the city is still rebuilding its soul.Margaret Hale is an anomaly in Restoration England: an independent, guild-recognized apothecary and botanist who rebuilt her Cheapside shop after the Great Fire and answers to no patron but her own discipline. Her knowledge is precise, dangerous, and carefully contained-recorded in a physick book she guards as fiercely as her glasshouse of poisonous plants. Étienne Moreau moves in a different world. A French physician trained on the Continent and bound by loyalty to Charles II, he occupies an uneasy place at Whitehall-valued, watched, and never entirely safe. When two palace servants die under suspicious circumstances, Étienne is quietly tasked with discovering the truth without disturbing the fragile order of Court life. The investigation leads him beyond royal walls and into Margaret Hale's domain, where poison is studied rather than denied and dangerous knowledge is preserved instead of erased. As evidence points to a deadly plant cultivated within the Palace gardens themselves, Margaret and Étienne form an uneasy professional alliance-one built on restraint, mutual respect, and the shared understanding that truth is often more threatening than any crime. Set against the political intrigues of Charles II's court, the religious tensions of post-Civil War England, and a world poised between medieval alchemy and the emerging Age of Enlightenment, The Poisoner's Garden is a quiet, intelligent historical mystery about power, knowledge, and the cost of remembering. Justice here is not decided by law-but by who controls the story. This first novel in the Restoration Apothecary: A Hale & Moreau Mystery series introduces a partnership defined not by romance or oath, but by careful witness-and a garden where the most dangerous truths are kept alive.