"I assure you that the most winning woman I ever knew was hanged for poisoning three little children for their insurance money." Sherlock Holmes to Dr. Watson in The Sign of Four. Early 1902 - On the eve of Newgate Prison's demolition, Watson spies Holmes leaving a public sale of the prison's miscellany in the company of a beautiful stranger and in possession of an unusual trophy: the death mask of a woman who, more than twenty years earlier, had...