For the last time, I’ve watched Slow Horses before reading the novel on which the TV series is based. From now, it’ll be novel-first. That’s interesting because in this fourth series the TV producers choose to differ in small but important ways from Mick Herron about who should do what. The dynamics are different on Spook Street. But no one would ever say that, because it’s a terrible line. And, as usual, the writing is top notch. Spook Street is highly regarded within the Slough House series: it shoulders big, meaty themes but wraps them up in a plot with pace and prose with quips. 

Mild spoilers follow.

As usual, River Cartwright is in the thick of the action, and not only because he never saw a loose thread he didn’t want to chase. River’s surrogate fathers – his boss, Lamb, and his actual grandfather the OB, now suffering from dementia – are joined by a new kind-of professional father as there’s a new, male, First Desk. But Spook Street also introduces River’s birth father and half-brothers who have a living arrangement that is simply horrific and which unspools with catastrophic effects both in the ‘real’ world but also within MI5. So you could argue that this is an instalment that is about fathers and role models and what people will do for (or to) their family. 

Part of that family, of course, is Catherine Standish, who dramatically resigned at the end of the last novel/series but who’s still very much part of things. ‘She’d been kidding herself if she’d thought she’d escaped Slough House.’

But I mentioned some of the dynamics differ between the two formats. As well as some slight differences in who gets to do what spy stuff, we note the arrival of Claude Whelan as First Desk changes things at the Park. In the TV show, Whelan is completely outmanoeuvred by Diana Taverner: it’s implied that she may have turned down his role which surprises us but we could accept it. The novel makes it clear that the fall of Ingrid Tearney nearly took down Lady Di as well: the price for remaining was to withdraw her ambition. And Whelan is not quite as pathetic on the page. There’s an operational decision which is made by Whelan on TV but Di in print, which makes me like her considerably less. The dynamic between Di and new head dog Emma Flyte is different, too: there is clearly trouble brewing between them but Herron’s Flyte has more agency.

J K Coe, whom we’ve met in The List and Nobody Walks, is now a slow horse. His previous experiences have wrecked him but at heart he retains his psych eval skills. There’s a moment when Shirley wants to execute a perp who has been captured and who is chained to a radiator. Coe talks her down from the decision. She gives Coe the gun. Coe shoots the perp three times in the chest. For all the references to James Bond (usually made by Jackson Lamb and usually directed unkindly at River’s tendency to act before thinking) here is someone literally issuing himself with a licence to kill. Catherine is appalled, but later that night Coe feels that he will sleep ‘dreamlessly’ for the first time in over a year. Did we mention these people are broken?

If Real Tigers explored the extent to which the Slough House folks are pawns for the adolescent games played by the powerful, here we face a different level of weariness. The situation surrounding Frank Harkness feels unusual if plausible (especially if considered a satire on the effect of conspiracy theories) but of unutterable bleakness. Herron uses the sheer momentum of the novel to deflect. On the screen, Moira Tregorian provides comic relief.

Yet again Herron has us on the side of his characters – rooting for them, angry for them, giggling at the silliness with which they break the monotony of their days. They are in no way heroes to emulate. And their boss, Lamb, remains an enigma: a man who can execute brilliant spycraft and with a true sense of loyalty to his joes, but who buries all his positive qualities from human sight. We can’t bear to look away.

Our other Slow Horses/Slough House coverage:

Slow Horses

Dead Lions

The List

Nobody Walks

Real Tigers

London Rules