This is more than just mystery and history, it is well written with much to keep you going to the end and wishing for more. Sarah Penner has a deft hand at guiding the reader through London, down onto the Thames embankments learning of the Mudlarks and from there into the twisting turning lanes of the old city in the late 1700s. There are two stories and they link in beautifully, never confusing, as the characters cope with their own problems. On the one hand the apothecary helping women with her herbs and tinctures hidden well away from the city around her where no man would find her nor even dream she existed. On the other hand there is Caroline, escaping from the distaster her husband has visited on their marriage by his affair Caroline discovered just days before they were supposed to take the trip from Ohio to London to celebrate their tenth anniversary. Instead she comes alone, upset and deeply angry by his conduct. In London and alone for the first time in her life, as she explores the small vial she discovered she finds that her life was not what she really wanted and so this trip is the beginning of how things might be in the future. Both women have learned from hard experience that men are not always as they thought them to be, and each in her own way discovers that life alone can be rewarding. There is no let up from intrigue, interest, and many a deep and meaningful awareness shared only by the women though separated by over two hundred years. It seems nothing changes and it is through her search for the apothecary that Caroline finds her own way through the life she has led for the past ten years. I was gripped by the book and found it hard to put down. The characters are very real as is the area of London both women found themselves living in. It was hard to finish and I tried my best to delay the ending but - as all good things do, it came to an end and I was immediately looking for more books by Sarah Penning. So far, this is it, and I now wait to see if there are going to be more, for she is surely an imaginative writer with a sense of true tension in her story. If you love a bit of mysterious history and enjoy finding how women, long kept under by men, have had their own ways of dealing with life under their thumbs, then this is for you.