CONTAINS SPOILERS

As someone who tries to promote public health, it pains me to say it, but smoking can save your life. But the circumstances under which this can be true are quite limited. One example occurs in the fourth episode of the sixth season of Slow Horses. Jackson Lamb lights up in a Shake Shack to cause a scene and enable him and an accomplice to escape from capture by the bad guys. I should point out that such scene would not have been possible before the restaurant smoking ban – in the old days, Lamb puffing away wouldn’t have caused an eyebrow to be raised – so perhaps it’s a win for public health after all.

The showdown in this episode between Lamb and Harkness is a highlight of the series so far. Both men are, officially, on the decline. Lamb is no longer in his ‘Bowie period’; Harkness is reduced to hiring in goons who are even less competent than the slow horses at their worst. But both men know that the other is still capable, and as they metaphorically circle each other, seeking information and advantage, there is mutual respect. Indeed, when Harkness in an earlier scene, tells the hapless care home receptionist that Lamb is ‘one of the best’, we know that there’s truth among the attempted charm. And when Lamb and Nesmith walk free, Harkness’s smile is not just an attempt to deflect the embarrassment of Nesmith’s accusations but a rueful acknowledgement that he’s been bested.

But much as we may have enjoyed the Frank and Jackson tête-à-tête, the soul of this episode lies in another encounter between two professionals, which results in the death of J K Coe at the hands of the Russian agent we know as Jim. Their interaction is matter-of-fact – they both know that at least one of them won’t survive the encounter, but there’s a courtesy and curiosity and even a little banter over pension arrangements. Originally working in psychological evaluation on the HR side of the Service, Coe was tortured and then banished to Slough House due to dumb luck and being on the wrong end of a scheme devised by former First Desk Ingrid Tearney for her own personal advantage. He seems to be coming to terms with his post-trauma healing being directly related to a rising kill count. And yet some observers would have assumed that he was happier in his skin than some of his Slough House colleagues. He has shown courage and a certain clarity and unwillingness to be pushed around. Shirley liked him, and River was unnerved by him. As with Min, as with Marcus, he will be much missed among the fandom. What a waste.

I wouldn’t be surprised if the final two episodes of this series work as a creative whole, rather like the showdown in the archive in series 3. This episode sees a great deal of positioning towards a spectacular resolution. Jim and Jane seem to have had some sort of tracker on Sid, River and Coe, as they seem to have no problem with following them. Sid is captured. River runs though…the car park. I bet you all the money I have in my pocket against all the money in your pocket that the nearest motorway service station does not sell a sign with ‘RIVER’ on it. Diana, who would no doubt argue that she had no choice, betrays Sid but has the grace to look sad about it. Flyte, who has been fired and has no reason to put herself in danger, deploys quality spycraft to find out who Harkness is meeting. Turns out he’s contracting for the Russian GRU, which is both a pivot and a natural destination for the former CIA man. Speaking of destinations, it looks like matters will be settled at Diana Taverner’s weekend gaff. Hope she’s insured. The shots from outside of Catherine, Louisa, Moira and Shirley exploring may be cinematic but if I were hiding from someone wanting to kill me I think I’d draw some curtains. Admittedly, these guys have had training and experience in the field. But as Moira reminds us, even a bunch of summers in the Yorkshire Dales don’t necessarily give us the skills we need. What happens next is anyone’s guess. But, kids, don’t smoke. It won’t always save your life.

Episode 5, Sayonara, will be available on 14 October 2026 on Apple TV.

Find the rest of our Slow Horses coverage, including reviews of all the Slough House novels and associated stories, and episode recaps of series 5 and 6, here.