As the dustjacket of the original hardback tells us this story is about CHCL3. It is also about sexual taunting during childhood leading to a perverted adult view of sex – though that is more difficult to illustrate on a dustjacket. The story cannot be described as a whodunnit, as the author identifies the perpetrator in the prologue, and it is not really even a why-did-they-do-it, the prologue again gives most of the answer. It is a combination of Crown Prosecution Service (that's government appointed lawyers in the UK) and police procedural written with an insider's knowledge and experience.
The book was first published in 1991 and reading it in 2020 the working class London environment and people could be as distant as an Ealing comedy. It wouldn't have been a surprise to have had one of the humbler characters saying to a police inspector, “Cor blimey, guv'nor. It's a fair cop,” and there are one or two remarks about the Asian community that would probably be edited out today. Having said that it is a very well structured tale of deduction and pursuit, most of the deduction coming from Helen West and the leg-work from Detective Superintendent Geoffrey Bailey and his male cohorts. The chaps are fine when it comes to obeying orders and enforcing discipline yet they do seem to struggle with rational constructs and reasoning.
The characters and relationships are interesting even if there is a strong hint of the lawyer's love of the most distorted mentalities being the product of their upbringing. Pip, the kindly chemist, does away with his wife, and comes close to killing another woman and her young son but by the end this gentleman, who is as loopy as a daffodil, deserves care and a patient ear to listen to the grinding misery of his life story and that of his equally loopy mother. The bomb disposal bit at the end doesn't add much apart from providing an empty set on which the actors can play out their dramatic finales. It has a slow start but it becomes a page turner as it progresses.