The Sins of the Wolf book by Anne Perry

"Give her a good murder and a shameful social evil, and Anne Perry can write a Victorian mystery that would make Dickens's eyes pop." The New York Times Book Review.
A William Monk mystery by the author of "The Hyde Park Headsman."
Nurse Hester Latterly finds herself well-suited for the position of accompanying the elderly Mary Farraline on a short train journey to London. Hester's sole duty on the trip will be to make certain that her charming patient remembers to take her heart medicine. But once aboard the train, Hester finds herself not so well-suited after all. Her patient dies during the night -- of natural causes, it is assumed. Then a piece of the dead woman's jewelry turns up in Hester's possession, and she is arrested for common theft. Then an autopsy reveals that the old woman was poisoned. And suddenly Hester is charged with murder. Can private investigator William Monk find both a motive and a calculating killer amongst the snobbish Farraline clan before Hester Latterly is hung for a crime she did not commit?