Slow Horses season six: Dry, acerbic and reliably the one show you look forward to every year

There are four terms to describe the speed of a horse – walk, trot, canter and gallop. When it comes to production turnaround times, Slow Horses isn’t walking around the paddock, it’s galloping down the straight.

Leaving aside the ick of horse racing, you have to really give credit to Slow Horses for always coming back on TV when you expect it to, stealthily embedding itself as one of those beloved – and reliable – shows you look forward to every year.

The series returns for its sixth season today, which is hard to believe because it feels as if it’s still a pretty fresh series, even though it was announced earlier this morning that it has been renewed for an eighth season.

Think about that. Eight seasons! In this post-Covid streaming era, that’s basically unheard of. Most shows are culled after one or two chapters thanks to those opaque calculations streamers use to determine the value of series not by quality or even ratings, but by whether or not they signed up enough new members.

So, Slow Horses must be doing something right. It probably has something to do with its superb performances from the likes of Gary Oldman and Kristen Scott Thomas, its acerbic humour, and its propulsive plotting that makes you forgive some of its more outlandish twists and turns.

It’s a spy thriller, it’s supposed to stretch the realm of believability, and we’re willing to give them that leeway if everything around it works.

Adapted from the popular novels by Mick Herron, Slow Horses is concerned with a group of reject operatives in the British intelligence service. They’ve all stuffed up, rather monumentally, at some point, so have been sent to a halfway house in the hopes they’ll quit without further disgrace.

The flatulent leader of the crew is Jackson Lamb, played by Oldman as a grossly unkempt Cold War-era spy who cares nothing for graces, but is, in his heart of hearts, someone who cares whether his agents survive or not.

That’s the core story of this sixth season, which sees former Slow Horses turning up dead in seeming accidents. But Lamb can see through it and knows they’ve been targeted by assassins.

The question is why, and what does it have to do with his team being wiped from the MI5 databases?

This season sees the return of a character absent since the premiere episodes (spoiler alert, unless you’ve read the books or have even watched the trailer) with Olivia Cooke reprising her role of Sid Baker. Sid’s re-emergence is a reminder of the great chemistry between Cooke and Jack Lowden, who plays River Cartwright.

The team, which also includes Standish (Saskia Reeves), Roddy Ho (Christopher Chung), Shirley (Aimee-Ffion Edwards) and Coe (Tom Brooke), are sent on the run, while drawing others into their orbit, such as Hugo Weaving’s menacing former CIA agent, now rogue operative and also River’s secret dad.

Not everyone survives the six episodes, which is not really a spoiler because Slow Horses has always been pretty unsentimental about killing off at least one person in its ensemble every year. Knowing that keeps the stakes high.

This season is the first without its original showrunner and writer Will Smith (not the slappy one), and it’s tempting to look for whether much has changed without his hand. Perhaps it’s a little less sharp, and there’s maybe one too many subplots going on (you need one of those red string crime boards to keep everything straight).

But Slow Horses stays in its lane in terms of delivering what you want from it, which is a compelling thriller with a dry-as-London-gin sense of humour and an Oldman performance so abrasive that only he gets away with it.

May it live beyond its promised eight seasons.

Slow Horses is on Apple TV