For those unfamiliar with the series, the concept is simple, if unusual. Central to the story, and narrator, is Horowitz himself in his real life persona of author and TV screenwriter. The fiction begins with the presence of a former police officer called Hawthorne who now works as a private investigator. The pair originally teamed up when Horowitz hired Hawthorne to provide him with real life mysteries that could be turned into CriFi plots.

Here, things become even more self-referential, as the first book in the series, The Word is Murder, is being turned into a major feature film, but the production, filmed in Hastings, the setting for Horowitz’s finest creation, Foyle’s War, is beset by problems.The screenwriter, producer and director are at each other’s throats, the project is way over budget already and the killer comes – literally – when the actor playing Hawthorne, David Caine, is found dead in his Winnebago, an expensive Japanese kitchen knife embedded in his throat.

Both Horowitz and Hawthorne are quickly called in by the Sussex police to help with the investigation. There are some tasty suspects. James Aubrey is Caine’s agent, but was about to be sacked, despite having played a huge part in the actor’s rise to fame. Teresa de Leon, the producer, having just been filleted for cash by a family dispute, knows that her only salvation is an insurance claim on the abandoned film. Next in the queue is director Cy (Cyril) Truman. He is, as they say, as camp as a row of tents, and admits that he fancied David Craig with a vengeance, and had done all in his power to boost the actor’s career. But was his largely unrequited passion enough to provoke him into a savage knife attack? Then we have the screenwriter. Horowitz is rather naughty in giving us a complete disconnect between her Christian name and her surname. Shanika Harris speaks in a studied Estuary English, and is as woke as a dawn chorus blackbird. She met Caine when she was a student, and was seduced by both his dynamic good looks and his Thunbergian zeal for the the environment and his hatred for those who enjoy a decent steak. Could the revelation that Caine occasionally ‘batted for the other side’ have provoked a frenzied attack?

Just over half way through the book, there is a dramatic shift in the narrative. Horowitz, knowing the stars’ Winnebagos bear the characters’ names, not than those of the actors, wonders if Hawthorne himself may have been the target, rather than the actor. Hawthorne reveals that there is, indeed, someone in Hastings who hates him with a vengeance. We then learn the story of the Murder at Foss Hall, which was Hawthorne’s first case as private detective. In a (rather large) nutshell, Rupert, the son of the Foss Hall owners, was involved in a fatal road accident. Duncan McClintock, the estate factotum, covered up Rupert’s culpability, but blackmailed the young man. When McClintock went missing, presumed dead, his blood was found in Rupert’s car. Hawthorne, a local man, was hired by the family to extricate Rupert from the mess. The result was that Harry Morgan, another estate employee, was convicted of the crime, and it is his widow – a barmaid in a Hastings pub – who has nursed a visceral hatred of Hawthorne since her husband’s death.

The detecting partnership between Horowitz and Hawthorne is Holmesian in one sense. Hawthorne is much the sharper of the two and frequently has to point out clues to his more affable and conciliatory partner. They aren’t even friends, let alone companions, Hawthorne never having had to bother with the drinks party social choreography that writers have to learn in order to pitch stories to agents and sell TV projects to programme commissioners.

Despite one or two interesting discoveries by the fictional Horowitz, it is Hawthorne’s attention to detail that closes the case, and the real Horowitz presents us with two elaborate but elegant solutions to two different murders. You can read my reviews of previous books in the series – The Word is Murder, The Sentence is Death and Close to Death – by clicking the titles. A Deadly Episode will be published by Century on 23rd April.