When the prompter falls dead during the second act of Richard Wagner's Die Walküre during a matinee performance at the Metropolitan Opera, as one can imagine, it causes quite a stir, especially when it is discovered that the deceased, a one-time world-famous Heldentenor, has been poisoned. The detective assigned to the case, Lt. Quentin, finds himself immersed in the back-stage drama of professional opera. His task is made more difficult when he decides that it had really been the star soprano who had been the intended victim, and not the prompter. Will he be able to solve the case before there is another Metropolitan Opera Murder?