It is the middle of the night ...The road is deserted ...A killer is waiting ...
Two traffic officers are killed on an isolated mountain pass in North Wales. Inspector Drake is called to the scene and quickly discovers a message left by the killer - traffic cones in the shape of a No 4.
The killer starts sending the Wales Police Service lyrics from famous rock songs. Are they messages or is there some hidden meaning in them?
Does it all mean more killings are likely? When a politician is killed Drake has his answer. And then the killer sends more song lyrics. Now Drake has to face the possibility of more deaths but with numbers dominating the case Drake has to face his own rituals and obsessions.
Finally when the killer threatens Drake and his family he faces his greatest challenge in finding the killer before he strikes again.