Polite society, poisoned from within. And the only person who can prove it is the apothecary nobody thinks to ask.

Charlotte Sedgwick inherited her father’s shop three years ago, along with his trade, his account books, and the particular problem of being a woman who compounds medicines for a town that would rather trust a physician’s guess than a tradeswoman’s measure. She knows every grain and dram that passes through Sedgwick’s. So when a preparation from the respected Dr Halloway leaves a patient worse instead of better, Charlotte is the one person in Marchford equipped to ask why.

What she finds in the account book is a death too convenient to be accidental, and a physician whose good name is worth more to this town than the truth. Charlotte measures everything carefully, in exact proportions, with no room for guessing, and someone in Marchford is about to discover that applies to murder as much as it does to medicine.

The Poisoned Tonic opens The Charlotte Sedgwick Mysteries, a series of Regency apothecary mysteries where chemistry, class, and quiet female expertise solve what polite society would rather leave buried.

Perfect for readers of scientifically grounded historical mystery, formidable tradeswomen heroines, and Regency-set puzzles solved by evidence rather than rank.