With his on-off lover Joanna away with work, Detective Inspector Bill Slider almost welcomes a call-out to the BBC TV Centre at White City. Roger Greatrex, celebrated music critic and opera aficionado, appears to have topped himself - only minutes before he was due to appear live on a quiz show.

But there are signs that the body has been interfered with, and Slider suspects murder. One fellow panellist is known to have quarrelled violently with Greatrex. two members of the production team have motives, and nobody in the building has a proper alibi.

Slider is under pressure to make an arrest, and all his instincts are at odds with the evidence. But a dangerous killer is on the loose, and could kill again...