The Egyptian Avenue at Highgate Cemetery

MIDWAY through reading the latest Cormoran Strike novel by Robert Galbraith (aka JK Rowling) I sustained an injury heartlessly described by my husband as “The Ink Black Eye.” Losing your grip on a book that weighs in at a hefty 1,012 pages can do that… especially if you’re reading it in bed and accidentally nod off.

That’s not to say The Ink Black Heart is soporific. Far from it. This complex and gleefully gothic story of murder and murky doings online gallops along, taking inventive detours, loops and twists at every opportunity. There’s just rather a lot of it.

The last time I encountered so many characters in a novel, I was studying European literature as part of my English degree. Spreadsheets had yet to be invented in the early 1980s, but I remember pinning a diagram to the wall of my student garret detailing everyone in War and Peace with additional notes on how they were related to each other.

By page 700 of The Ink Black Heart, I wished I’d done something similar, especially as the detritus-strewn brain of a menopausal 50-something is no match for the virgin plains of an 18-year-old mind.

Nevertheless, I forged ahead and, in the end – with some reservations – I’m glad I did.

Fans of previous Strike novels (or of the excellent and notably shorter TV adaptations starring Tom Burke as the eponymous one-legged, but sexually devastating, private detective and Holliday Grainger as Robin Ellacott, his sweetly pulchritudinous partner in crime solving) will need little introduction to the basic set up.

Strike and Robin work with a small team of gumshoes from a ramshackle office in Denmark Street. After many trials and tribulations, they usually get their man… or woman. En route to the denouement, the reader is privy to the sizzling but unspoken “will they, won’t they?” frisson between them.

It’s pretty much business as usual in The Ink Black Heart.

The title refers to a macabre but quirky fictional animation based on Highgate Cemetery. The dark, anarchic humour of the series has attracted a legion of devotees, but in the shadowy corners of the internet, some fans have developed an unhealthy obsession with the cult cartoon and those behind it. Co-creator Edie Ledwell has become the particular focus of malign and misogynistic online attacks.

When Edie is murdered in Highgate Cemetery suspicion falls on the anonymous players and moderators of an online game inspired by the cartoon. Strike and Robin are employed to discover the true identity of “Anomie”, one of the key figures in the game. Feared and revered by the players, the charismatically toxic Anomie has manipulated the possessive passion of the fandom and orchestrated a persecution campaign against Edie. But did they kill her?

JK Rowling proves to be the perfect guide to the fetid recesses of the internet where aliases and gamer names shield identities and motives. It’s clear that the author knows only too well how it feels when fans grow up to bite the hand that created the thing they loved.

There are plenty of parallels to Harry Potter’s magical world. The fantastical graveyard cartoon is convincing and richly imagined.

The looming menace of Anomie in the game brings to mind Lord Voldemort, while Strike, Robin and their rag-tag band of private detectives could be seen as grown-up versions of the boy wizard and his mates, here battling alt-right politics and incels instead of black magic.

The Highgate Cemetery setting is more than gothic window dressing. Rowling neatly revisits the grisly story of the artist and pre-Raphaelite model Elizabeth Siddal, who is buried there. Elizabeth was married to Dante Gabriel Rossetti and was his muse. When she died he theatrically added a notebook of his unpublished poems to her coffin. Later, regretting the financial implications of this literary loss and realising that it would be more bother to write them again, he dug up her body to retrieve them. Like Elizabeth, Edie Ledwell is buried in Highgate cemetery.

The Ink Black Heart is fascinating and immersive but sometimes this reader felt there was just too much of it. The online parallel conversations between anonymous players of the game – presented almost as scrolling screenshots – is clue-packed and cleverly done, but after a while it begins to feel like homework. There are just too many of them. The same can be said of several of the male suspects who inhabit the “real” world beyond the game. When you have to flip back 200 pages or so to remind yourself who someone is, it’s irritating rather than intriguing.
Which brings me to the tantalising possibility of romance between Strike and Robin. The fact that these two brilliant, intuitive detectives can’t deduce that they’ve fallen head over heels in love with each other is initially charming, but – by page 1,012 – infuriating.

Perfect for Halloween, The Ink Black Heart is good morbid fun. It fizzes with ideas and compulsive creative energy that could – and probably should – have been reined in by a stronger editor. Karl Marx is another famous resident of Highgate Cemetery. It’s tempting to imagine he and JK Rowling discussing the importance of economy.

• The Ink Black Heart. By Robert Galbraith, Little, Brown, £25