In the early hours of a quiet, weekend morning in Manhattan's Diamond District, at the scene of a brutal triple murder, the killer left behind a half-million dollars' worth of gems at the scene. As more crimes follow, it becomes clear that the killer's target is not gems, but engaged couples themselves. Then a witness is left alive. Vimal Lahori, a young diamond cutter, can help Rhyme and Sachs blow the lid off the case-- but has gone into hiding. They must track down Vimal before the killer can correct his fatal error.