After years spent away, Lady Evelyn is at long last back in her home city of London and she has returned with a rather controversial plan. The Carlisle Detective Agency is born, and it does not take long for the bodies… ahem, cases, to start piling up. With her friend and assistant Hugh, Evelyn embarks on the quest to solve the crimes. Yet the London she encounters is not the London of her coddled youth, and she is forced to learn that there is more to discover than the identity of a murderer. It isn't only her city which reveals it is not what she always believed it to be, but the people she encounters as well. Secrets are revealed that have her thinking twice about everything she thought she knew about the society in which she grew up.
Evelyn's love for her hard-won independence confronts her with yet another mystery, whether she is ready or willing to give up any of it for marriage. And then there is the arrival of rather a familiar face in London, one Daniel is none to pleased to see. Evelyn must find not one but two murderers, as well as make a decision that could determine her future. From the mansions of Mayfair to the dark alleys of Whitechapel, can Evelyn catch the killers before another life is taken?