Is Slow Horses slowing down?

Since it launched in 2022, Slow Horses has been one of the most reliable television treats for all its four seasons. Based on the excellent novels by Mick Herron, it has focused on a group of “misfits and losers,” as none other than Mick Jagger sings over the credits, who have all been semi-exiled from MI5 for various misdeeds. They have ended up in the purgatory of Slough House, where they are stuck doing various soul-destroying administrative tasks until they quit. The joke is that most of them are good at their jobs (although not without some seriously challenging interpersonal issues), led by Gary Oldman’s superspy Jackson Lamb, whose belching, flatulent and deeply unhygienic exterior belies a razor-sharp mind and a keen grasp of human nature.

The last season saw the James Bond manqué River Cartwright (Jack Lowden) find a father, and the Slough House team a nemesis, in the form of ex-CIA operative Frank Harkness. It raised the stakes to new and giddy levels, and in the casting of veteran baddie Hugo Weaving seemed to introduce a Moriarty-esque antagonist for the ages, which is why it’s relatively disappointing that season five begins with a return to familiar territory. There’s an apparently motiveless massacre been committed by a lone shooter who swiftly gets a sniper’s bullet in the head, two men (one Asian and liberal, one white and right-wing) running to be the new mayor of London, and the various spooks are struggling to cope after the death of one of their number in the last series. Oh, and irritating tech support Roddy Ho has an unfeasibly attractive girlfriend. How does all this tie together?

The appeal in previous seasons of Slow Horses has been half in the deliciously convoluted plotting, playing with tropes of espionage established by John le Carré and Ian Fleming and subverting them for all it’s worth, and half in the interaction between its characters, which at its best has the tight scripting of a great sitcom. This season will be the last from showrunner Will Smith, which on previous form would be a tragedy, but judged by the opening episode, something here is not quite right. The dialogue too often mistakes swearing for wit – one conversation between Lowden and the fiery Shirley Dander (Aimee-Ffion Edwards) simply consists of the two saying “Fuck off!” “Fuck you!” to one another. And one’s heart sinks at yet another show that looks as if it’s going to revolve around the far right and men’s activists as villains.

Still, it’s too early to write things off yet. Oldman has increasingly described Lamb as his signature role, and he gets all the best lines and situations, reveling in the chance to play a character who doesn’t ask to be liked but ends up being the center of gravity anyway, and there are hints that the rich comic elements of earlier series might yet reappear. I enjoyed Ted Lasso actor Nick Mohammed’s brief appearance as the platitudinous mayoral candidate Zafar Jaffrey, speaking in his special official voice even when there are only a handful of people in the room, and Christopher Chung excels at conveying Ho’s odd mixture of smugness and childishness.

But for all its surface pleasures, I am concerned that the show is being written and produced at such a clip – five seasons in three years is a lot – that nobody is taking the time to reflect on why it’s built up such a persistent cult following that is always threatening to turn it into a big mainstream hit. Two more seasons are already commissioned, but I am beginning to wonder, for the first time, whether the Slow Horses might yet need to be put out to pasture on a rather permanent basis before outstaying their welcome.