When she hears a pounding on the door of her rooming house late one night, Lucy Barnstable hurries to answer it, hoping her missing father has returned. Instead, a handsome stranger falls at her feet, his clothing soaked with blood and his face bearing the marks of a thorough beating. In his hand, he clutches a handbill her father had issued, advertising his services as a detective in the mode of Sherlock Holmes. Assuming from this piece of evidence that he knows something about her father's disappearance, Lucy brings the stranger into her house to treat his wounds and, hopefully, find out what has happened to her father.
She is disappointed when it becomes apparent that the stranger has no idea who he is or why he had the handbill. Still certain that the stranger can lead her to her missing father, Lucy claims to be her father's assistant, the Watson to her father's Holmes, and she insists on helping the stranger recover his memory and his identity. It soon becomes apparent that their two mysteries are connected and both are tangled up with the Eye of the Devil, a fabulous diamond which is to be presented to Queen Victoria as part of the celebrations of her jubilee.
One of the trickiest elements in writing a story that mingles two genres is finding the proper balance between the two. Failure to find the balance can result in readers of both genres leaving the book dissatisfied. In this mystery-romance, it seemed as if the author tried to achieve the balance by focusing first on one element, then on the other. For me, the result was that I felt a little shortchanged both as a mystery reader and as a romance reader.
Lucy is a fun character, fond of leaping first and looking after, someone for whom the phrase, "Fools rush in where angels fear to tread," might have been coined. The stranger's amnesia is handled well, with little flickers of knowledge, such as the realization his name is James, illuminating the darkness as the story progresses. My only quibble with him was that at one point in the story, he became determined to believe the absolute worst of Lucy on rather flimsy evidence. I don't have a quarrel with the conclusion he reached; what I mind is that he latched onto it as the truth without entertaining other possibilities. This seemed rather out of character for him and came perilously close to the dreaded Big Misunderstanding.
Overall, Devil's Diamond is a pleasant read, with a strong mystery alternating with an agreeable romance. If you're looking for a light, entertaining book, this may be the one for you.