This is an amazing story told by an amazing author. The book starts a little slowly and the reader or listener has to get used to the back and forth in time from present day to the mid-1800's, but the story is worth it.
Present day Julia is starting over as an ex-wife, remodeling a 100 plus year old house in burbs of Boston. She finds a skull in her garden and this starts the flashbacks to the story in 1830 of Rose Connelly trying to keep alive from the hands of the Reaper, a serial killer who seems to be targeting people from the hospital where her sister has just given birth.
There are historical figures as well as fictional and the blend is done quite seamlessly. The reader has a view in medical studies in that era, the progress of the medical miracles and the sheer ignorance of supposedly intelligent men who could not figure out that washing hands and using clean instruments and towels would help prevent the spread of disease and death. The high mortality rate that would provide bodies for study by the medical students, except that it was against the law. We meet 'resurrectionists', the grim diggers of graves to provide bodies for the medical schools. Makes the reader shudder and lean forward to see what is going to happen next.