Resurrection Row by Anne Perry
It was the most incredible thing: a corpse sitting in an empty hansom cab - and it wasn't just any corpse, but the body of a peer of the realm. To Inspector Pitt and his wife, Charlotte, it was sheer lunacy. Whoever would want to unearth a decently buried old chap like Lord Augustus Fitzroy-Hammond? The doctor insisted that the death had been natural. But there was certainly nothing natural about any of this as far as the police were concerned. And Inspector Pitt was determined to unearth the truth - even if the digging could kill him...