The tone may indeed be witty and elegant, but Slider feels quite the opposite when his violinist lover, Joanna, goes off to the Glyndebourne opera festival to rehearse Don Giovanni, leaving Slider ill at ease in her London flat. Perhaps fortunately for Slider's equilibrium, he's soon distracted by a call to the BBC television studios where Roger Greatrex, a celebrated music critic and opera expert, has apparently killed himself just before a scheduled appearance on a panel discussion show. Was Greatrex's death murder? There are signs the body has been tampered with, leading Slider to suspect he's not dealing with a case of suicide. But who killed Greatrex and why? Just before the show, Greatrex had a violent quarrel with one of the panelists. Two other members of the production team also had motives for murder, and nobody in the building has a proper alibi. When a surprise new witness turns up to cast suspicion on one of Slider's own, Slider is pressured to make an arrest. His instincts argue against the evidence, but a dangerous killer is on the loose and could kill again.