Book #9 of the Papa Pontivy series.
Claiming that he is tired of catching spies, Papa Pontivy cries for a simple murder case. He gets one immediately but soon finds that the death of his dinner host, a former colonel in British Intelligence, is murdered in his own home. Now he and Bernard Newman have a killer to catch but the killer has his own plans.
Marshall is very much involved in this case and has now been promoted to Chief Inspector. He is still with Special Branch though he is already involved in a murder investigation when approached by Pontivy and Newman.