When a house mysteriously explodes in the sleepy suburbs of south Oxford and a child goes missing in the aftermath, concerned neighbour Sarah Trafford is driven to seek the truth. As an art conservator, Trafford is way out of her depth, so she enlists the help of a private investigator, Zoë Boehm. However, the pair end up in a plot far more serious than Boehm’s usual work of checking credit ratings and tracking adulterous husbands.

This is the story of Down Cemetery Road (2003), the debut novel of writer Mick Herron, which has been adapted into an eight-part series by Apple TV. Down Cemetery Road is the second of Herron’s book series to be adapted by Apple, coming hot on the heels of the fifth season of the critically acclaimed Slow Horses, which centres on misfits and renegades navigating bureaucracy and corruption at MI5.

Like Slow Horses, Down Cemetery Road is fronted by British acting greats, with Ruth Wilson as art conservator Sarah Trafford and Emma Thompson as private investigator Zoë Boehm. It also exposes failings at the heart of British institutions, this time the UK government.

Read more: Slow Horses: high drama and comedy abound in this gripping spy thriller about reject spooks

Boehm and Trafford uncover evidence that the UK government has deliberately maimed its own soldiers during illicit chemical weapons testing on the battlefield (the Gulf war in Herron’s novel, Afghanistan in the adaptation). To an even greater extent on screen than on the page, however, this military premise feels like one of Alfred Hitchcock’s “MacGuffins”: something to get the narrative engines firing, rather than a theme for profound exploration.

As a conspiracy thriller, then, Apple’s Down Cemetery Road does not compare with such classics of British TV as Edge of Darkness (1985, exploring a shadowy expansion of nuclear power) and State of Play (2003, about corrupt links between politicians and the oil industry). But while it is politically thin, it is nevertheless satisfying as a TV spectacle.

One of the incidental delights in watching the series is to encounter stalwarts of British acting even in minor roles. Mark Benton, a PI himself in the long-running series Shakespeare & Hathaway, turns up here as an Oxford academic.

He momentarily emerges from his wineglass to reminisce about Sarah as a gifted student who memorised the whole of The Waste Land (including, he marvels, the footnotes). Sara Kestelman, best known for her career in theatre, is touching as a bereaved mother. Gary Lewis, the initially scornful father in Billy Elliot, is bracing as a Scottish skipper who believes Zoë and Sarah to be yet more English folk intent on telling “humble Highlanders” what to do.

But the star turns are Thompson and Wilson. Zoë’s sustained presence on screen actually represents a promotion from the novel, where she is surprisingly absent until the second half.

Thompson is visibly having fun as she breaks away from the buttoned-up gentility of films such as Sense and Sensibility, Howards End and The Remains of the Day that, even now, will define her for many viewers. Her language is as spiky as her punkish silver hair, such as when she talks of collecting her husband from “the fuck-up creche”.

Wilson, as throughout her film, TV and theatre career, embodies intelligence and curiosity as Sarah. We are alerted to her vigilance from the start, as we see her scrutinising a painting through her art conservator’s magnifying glasses. But if she looks outwards keenly, she has fewer opportunities as the series unfolds to turn her gaze inwards.

The adaptation is relatively uninterested in the inner lives of others, too. In Herron’s novel, even the frightening government operative Amos Crane has interiority, chafing at the bureaucratic confines within which he has to work. Here he is played by Fehinti Balogun as a robotic killer, seemingly incapable of feeling (other than briefly mourning his brother and, improbably, laughing at an episode of the BBC sitcom Keeping Up Appearances).

While characterisation is thinned in Apple’s adaptation, the action is thickened. Morwenna Banks and her co-screenwriters are unafraid to introduce fights and chases not found in Herron’s novel. In an especially thrilling sequence, Down Cemetery Road joins films such as The Lady Vanishes and Murder on the Orient Express in exploiting the suspense possibilities offered by a speeding train, with no opportunity to get off.

The spectacular sometimes takes a homelier form. The moment when Zoë eats a giant meringue is made striking when it shatters into sugary shards, an explosion scarcely less apocalyptic than that in the opening episode.

The moment is funnier than the repeated conversations between civil servant mandarin C. (Darren Boyd) and hapless underling Hamza Malik (Adeel Akhtar). Their scenes, offered as comic relief, come to grate and indicate a certain self-indulgence about the adaptation.

There are thoughtful sounds, too. Mozart’s Requiem is heard as the action reaches a deathly climax. And bebop jazz by Dizzy Gillespie plays over a scene of narrative discordance at the end of the opening episode. Particular thought has also been given to each episode’s closing music: songs such as P.J. Harvey’s Big Exit and Björk’s Bachelorette are witty, apt choices.

Over the final credits, we hear Billie Holiday’s I’ll Be Seeing You. With three more Zoë Boehm novels already written by Herron, it is an open question whether we will be seeing her again.