The Ink Black Heart carries on the old fashioned allure of Strike – however an excessive amount of is misplaced in translation

What connects Dune, The Lord of the Rings, On the Road, Cloud Atlas, and Inherent Vice? Answer: they’re all books that have been described at one point or another as “unfilmable”. Add to that list, then, The Ink Black Heart, the sixth instalment in a series of private detective novels by Robert Galbraith, a pseudonym for children’s author-turned-political lightning rod, JK Rowling. Set amid the trolls and edgelords of internet subcultures, this profoundly “online” story proves a challenge for the BBC – will they be able to turn it into another gripping instalment of Strike?

We pick things up in the aftermath of the events of 2022’s Troubled Blood: the personal relationship between Cormoran Strike (Tom Burke) and his business partner Robin Ellacott (Holliday Grainger) – a will they, won’t they of epic proportions – is as uncertain as ever, but their professional alliance remains strong. It needs to be. When a young artist, Edie Ledwell (Mirren Mack), comes to their agency asking for assistance with a stalker, Robin declines to help. But when she’s later found murdered, the Strike-Ellacott team are drawn into a dangerous world that revolves around Drek’s Game, a fictitious video game spun off from Ledwell’s much-loved cartoon, The Ink Black Heart. Can the secret to who killed her be found in the game’s chatrooms? Or is there something else going on related to the alt-right fascists in the real world?

Those who have read the book will know that much of the action takes place in verbatim transcripts of chat logs from within Drek’s Game. Naturally, this would not make for particularly scintillating television, and so most of the proceedings are relocated to the real world. The Ink Black Heart is a two-sided whodunit: who killed Edie and who is Anomie, the mysterious figure running Drek’s Game and, seemingly, the person pulling all the strings? “We find out who Anomie is,” Strike asks Edie’s lawyers, when they’re hired to investigate the anonymous harasser, “and what do you plan to do about it?” After all, what can be done about a spooky digital presence? This is a game of cat-and-mouse where the mouse can scuttle off under the floorboards of digital ephemera.

A slow burn: the relationship between the series main duo takes centrestage in this crime story (BBC/Bronte Film & TV/Rob Youngson)

There are a few big issues with the translation from page to screen. Reducing the centrality of Drek’s Game is arguably necessary, but it also robs the story of its most interesting dynamic: characters in the real world – the rakish life model, the disaffected former PA, the vulnerable hypochondriac – may, or may not, be the voices behind the anonymous participants in the game. This creates an intriguing shadow play (a whoisit as well as a whodunnit) within the novel that is largely dispensed with in its screen adaptation.

But the bigger problem is contraction. The Ink Black Heart is a doorstopper – over 1,000 pages in paperback, or almost 33 hours if you prefer the audiobook. Here, it is condensed to just four hours, which cannot do justice to the multi-threaded story, or the sheer volume of possible suspects (some of whom only get a scene or two before the denouement). There has been some judicious cutting (including removal of one of the book’s more controversial storylines) but the series is still caught between two stools. A less faithful adaptation might’ve worked better over the short run; a longer run might’ve worked better with the desired fidelity to its source.

Filming an “unfilmable” book means that compromise is inevitable. But the compromises made for The Ink Black Heart both defang it and render the mystery too abridged to be truly satisfying.

All the same, both the books and their adaptations are not really about crime, but the chemistry between Strike and Ellacott. Robin, emerging from a disastrous marriage (“I screwed up my marriage in less than a year,” she confesses); Strike, still drawn, inextricably, into the games of his ex, Charlotte (Natasha O’Keeffe). Once again, Burke and Grainger do fine work as people navigating their way towards romance with all the alacrity of the Ever Given cruising down the Suez canal. In a TV landscape where shows routinely get canned after one or two seasons, there is vanishingly little room for a proper slow-burn relationship. But here we have one of the few convincing, and compelling, long-term love stories left to the format.

The Strike series continues to have an old-school charm about it. Most detective dramas these days strive to be realistic, serious and brooding – it can all be very exhausting. Strike, meanwhile, seems content to be a throwback, which, ironically, makes it far more refreshing.

‘The Ink Black Heart’ is available on BBC iPlayer