Rhyme and Sachs return to New York from a honeymoon and find Manhattan’s diamond district terrified. Three people are tortured and brutally murdered in a secluded jewelry shop. Vimal Lahori, a young diamond cutter, walks into the scene and then runs barely escaping with his life.
We are left wondering about the motive of the perpetrator of the murders when a half million dollars worth of diamonds are left behind at the scene. Before long engaged couples are found murdered and the diamond on their ring fingers seem to be the motive. By this point Rhyme and Sachs are on the trail of the man now being referred to in the press as The Promisor. Vimal has gone into hiding since he knows that the killer is looking for him.
We learn a great deal of information about diamond cutting and the industry in general from this novel. The book is divided into five sections named for the stages that a rough diamond goes through before becoming a finished diamond: plotting; cleaving; sawing; bruting; and brillianteering. If these section names have relevance to the process used to investigate the crime it seems weak.
It was a twist and turn plot full of unexpected developments but that was not enough to make this book what it was expected to be.
