After a misjudged opening chapter ("the hot rush of longing between my thighs" being the relentless theme), the energy of Clark's writing really began to impress me. She's brilliant at conjuring up a sense of place, time and atmosphere: an early scene, in which she relates her spirited and foul-tempered heroine's long journey to London in a carriage, outshone every other such account I've read by miles, and had some lovely touches of humour. However, I started to wonder, after 100 pages, when the amazingly vivid descriptions were going to stop, and the story take the front seat.
The gruesome plot is interesting, and not as incredible as it might seem, but it didn't engage me enough, and I struggled to finish. (If it hadn't been for the excellent writing, I wouldn't have bothered.) I agree with the reviewer who felt that the apothecary Grayson Black, in being too remote from the narrative, is not quite the chilling, evil presence he is meant to be; I found him more of a sad, self-obsessed, opium-addicted victim of his times. Having said that, there's food for thought about the way in which the powerful have always used the powerless as cannon fodder.
I was planning to go on to read Clark's first novel, The Great Stink, set in the London sewers. (She doesn't half like writing about poo!) But now I don't think I can face it. That's a shame; like a number of other authors I've recently read, she has enormous talent, but falls short on how to pace and sustain a novel through to the end, and make readers care more about the plot.
In summary, I would avoid this book if you are: a) sensitive about issues of pregnancy, abortion and miscarriage; b) very squeamish, or offended by graphic references to bodily functions; c) the sort of reader who much prefers dialogue and pace to description. On the other hand, I would recommend it if you love getting lost in another world, and can enjoy dark themes and grotesque characters - but don't be surprised if it doesn't ultimately satisfy you.