Sarah Penner's debut novel, The Lost Apothecary, is an enthralling work of mystery, murder, trust, and betrayal. Set in an atmospheric London, Penner's immersive story flows skillfully from past to present, revealing the heartaches and lost dreams of three captivating main characters in a page-turningly tense drama that surprises right up until the final paragraph.

In 1791, Nella Clavinger is an apothecary who owns and operates an exclusive shop. So exclusive, it is hidden behind a wall in a storage room on Bear Alley, where she can watch prospective customers through a peephole. And it's hidden with good cause: Her herbs, bugs, and such are designed to provide women in need with the option – albeit a deadly option — to right a wrong they could not otherwise, in an era when women couldn't just walk away from abusive husbands, fathers, brothers, or employers. But Nella is a skilled apothecary who offers women a choice. Her tinctures (concentrated herbal extracts, which also feature the occasional dose of rat poison) can make a man problem disappear. But Nella has rules — lines drawn in the sand she believes she'll never cross.

Eliza Fanning is a 12-year-old lady's maid. An intelligent, loyal, and trusting young girl, although somewhat superstitious, she visits Nella on behalf of her mistress. She has specific instructions on what she is to purchase (and whom the tincture is meant for). But she is not ignorant of what Nella's vials contain or what they will accomplish.

In present-day London, Caroline Parcewell is visiting from Ohio on a vacation of sorts, celebrating her 10th wedding anniversary — but without her husband. She left him behind after his confession of infidelity. Caroline, a once-upon-a-time aspiring historian, is heartsick over his betrayal, yet mindful of the choices that led her to give up on her dreams of being a historian. But after her first touristy adventure, mudlarking (which refers to scrounging along the River Thames' shoreline for something old and valuable), these thoughts take a backseat to curiosity. She finds an old apothecary vial with markings that could be an address. After a visit to the British Library, Caroline's not-so-long-ago desire to discover the history of old things comes roaring back.

The Lost Apothecary is engrossing from the onset. Although some might be slightly appalled by Nella's profession, Penner immerses us in 1791 London, patiently revealing Nella's backstory and the circumstances that influence her decision to turn her mother's apothecary shop, once a place for healing, into a haven for betrayed women who believe they have no other choice but murder.

Refreshingly, this book is not a procedural or a study in the psychosis of a serial killer. What it does is create an affinity for the reader with Nella, Eliza and Caroline. We root for the three main characters, wanting them to find a way around the problems that escalate in surprising ways.

Also compelling is Penner's consistent return to themes of motherhood and impending womanhood. It creates a sense of humanity — in other words, I didn't feel guilty about not passing judgment on any of the female characters.

While The Lost Apothecary feels like it gets off to a slow start, Penner builds tension by planting us deep into each woman's psyche. Then as the characters dig in, she upsets their foundations and shifts their expectations; Nella, Eliza, and Caroline must think quick to avoid falling deeper into a ditch they don't see ahead. And neither do we, which only adds to the fun.

At one point, Nella says "You cannot be betrayed by someone you do not trust." But trust me, you can trust Sarah Penner's The Lost Apothecary to keep you turning the pages of a story that doesn't ease up until the very last sentence.

Denny S. Bryce writes historical fiction. Her first novel, Wild Women and the Blues, is coming this year.

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