Method of Revenge by Cara Devlin

Murder never shocks Leonora Spencer. Violence is a fact of life in Victorian London, and most of the corpses Leo attends to inside her uncle’s city morgue are its victims. But when she witnesses a woman’s death at a popular night club, and then follows a suspicious hooded figure retreating from the scene, Leo lands herself in the center of another complex Scotland Yard investigation—right where Detective Inspector Jasper Reid doesn’t want her.
In the several weeks since the unconventional Leo Spencer helped him solve an explosive case, Jasper has kept the willful morgue assistant at arm’s length. Now, the bride of one of the city’s most dangerous crime lords has been poisoned, and his primary witness is the very woman he’s been trying to avoid—if only because she is as fascinating as she is irritating.
Disregarding strict warnings to stay out of it, Leo insists on helping Jasper sort through his inquiry. When a death portrait of two mysterious children is found in the victim’s handbag, and an unsolved Jane Doe case that haunts Jasper resurfaces, he and Leo begin to question if more than one crime—and killer—is at play. But discovering the truth might also mean walking into a carefully laid trap.