Leslie Maughan, recognized for her keen mind, has unofficially been promoted to Scotland Yard’s first female investigator. Chancing upon a book of poetry once owned by a Peter Dawlish, convicted forger, Leslie delves into the details of the convict’s case and becomes convinced of Peter’s innocence. Befriending Peter after his release from prison, Leslie discovers a link between him, a lady of high society, and a princess, after the violent death of a butler who has his employer’s valuable emerald in his possession. The trail takes a twist when it’s discovered that Peter may have a child he knew nothing about, and that his landlady has been been using her home for more than room and board.