A forgotten history. A secret network of women. A legacy of poison and revenge. Welcome to The Lost Apothecary. Hidden in the depths of eighteenth-century London, a secret apothecary shop caters to an unusual kind of clientele. Women across the city whisper of a mysterious figure named Nella who sells well-disguised poisons to use against the oppressive men in their lives. Nella's dark world is no place for her newest patron, a precocious twelve-year-old girl named Eliza Fanning, but their unexpected bond sparks a string of consequences that echo through the centuries. Two hundred years later, aspiring historian Caroline Parcewell discovers an aged apothecary vial in the River Thames.