Slow Horses Season 6 Review: The Best Show on TV is Back

AppleTV’s Slow Horses Season 6 finds the rejects from Slough House, a dysfunctional team of MI5 agents led by Jackson Lamb (Gary Oldman), under attack like never before. As Slow Horse agent River Cartwright (Jack Lowden) deals with ghosts from the past, the rest of Slough House find themselves on the run as Diana Taverner (Kristin Scott Thomas) embroils them in a fatally high-stakes game of retaliation and revenge.

When I got access to Season 6 of Slow Horses over a month ago, I was incredibly excited. If you talk to me for more than a couple of minutes, you’ll soon hear me raving about just how brilliant Slow Horses is. How it is both a perfect spy drama and a hilarious comedy. How well-drawn its main cast of characters is. How it is one of the very few “Prestige TV” shows to consistently release seasons year after year without dropping in quality. So yes, it’s safe to say I stopped everything else I was doing and binged all six episodes of the season in one sitting.

“What did you think of the latest season of Slow Horses?”, I hear you ask, dear reader. What did I think of the first season of the show to not have original showrunner Will Smith (not that one) at First Desk? What did I think of their first attempt at adapting two of Mick Herron’s original novels instead of one? In as few words as possible? I adored it. In a few more than that? Slow Horses Season 6 shows that there is still plenty of life left in the Slough House rejects. Thanks to new showrunner Gabby Chiappe and returning director Adam Randall (who won an Emmy for his work on Season 4), they have managed to craft a season that rivals, if not betters, every season before it.

But I had a major problem after bingeing through all of Slow Horses Season 6. Just how the hell was I going to review it? I don’t mean in terms of avoiding spoilers for how the season ends, or who doesn’t make it out. That I can work around without issue. No, I was dreading having to write a review without mentioning a whole story thread that runs through the season, my favorite one at that. But thankfully, a few days before I finally sat down to write these very words (and yes, I spent over a month not knowing what to do), AppleTV released a trailer that revealed what I struggled to say…

OLIVIA COOKE IS BACK! Yes, Sid Baker herself, last seen having been shot in the head all the way back in the first couple episodes of Slow Horses Season 1, has made her triumphant return. And she is every bit the funny, dry-witted, exceedingly charming character she was, even with the trauma she has been through. As for how and why Sid is back, I won’t reveal that. It’s still best to keep some secrets. But what I will say is that Cooke’s performance is the highlight of the season. Getting to spend more time with her is a true joy, and her chemistry with Jack Lowden, with whom she spends most of her time, is off the charts. The way they go between constant bickering and genuine care (and maybe more) for each other feels so effortless. I love their dynamic on a deep level. I’m just so happy Cooke is back, and getting to act in something that is a complete left-turn to her work on House of the Dragon, while still demonstrating she’s one of the best performers to be working today.

As for Lowden, he continues to shine as the equally charming and pathetic River Cartwright. The way he has developed his performance over these last few years has been a joy to watch. Slow Horses Season 6 finds River dealing with various traumas, one being the return of his mercenary father, Frank Harkness (Hugo Weaving). These all compound to give Lowden a lot of great material to work with, but he also gets the chance to have a couple of true hero moments this season befitting even the greatest of British spies. And one line of dialogue towards the end of the fifth episode had me both swooning and cheering for joy.

I’m realizing as I write this that, being so excited to get to talk about Olivia Cooke’s return, I haven’t even name-dropped any of the other Slow Horses. As prior seasons have proven, the show is well-versed in balancing all its characters, and this season is no different. Gary Oldman’s Jackson Lamb, the awfully amazing head of Slough House, continues to be maybe the best character of the 2020s. Shirley Dander (Aimee-Ffion Edwards) and Catherine Standish (Saskia Reeves) are still two of the only competent people working for Lamb, even with the wealth of personal issues they have that rear their head in ways big and small this season. Despite having been the subject of a honeytrap last season, Christopher Chung’s Roddy Ho hasn’t learned any lessons, though he does get a small, heartbreaking moment of realizing the cost of spycraft in the finale that I absolutely adored. And finally, the mysterious Coe (Tom Brooke) gets some standout moments.

The remainder of the cast, both returning and new, are all, unsurprisingly, great. Ruth Bradley’s Emma Flyte continues to find her professionalism challenged by her dealings with the Slow Horses, while Kristin Scott Thomas’ Diana Taverner deals with the compromises inherent in finally having made it to MI5’s First Desk. Of the new cast members, it’s Lenny Rush who makes the biggest impact as a child caught up in the machinations of this season. His dynamic with both Oldman and Chung is a delight, and I honestly hope they find a way to keep him around for future seasons.

Before I close out my review, I do want to circle back to Adam Randall’s direction of this season. As previously mentioned, he won an Emmy for his work on Season 4 of Slow Horses (and gave us the perfect summation of who River Cartwright is), and it’s obvious to see why he won and was brought back for this season. The show has never looked more cinematic than it does under Randall’s direction, with the explosive confrontations of the finale delivering some of the tensest set pieces, and a looming dread for the safety of our beloved Slough House rejects, that the show has done. I wouldn’t be surprised if he’s up for an Emmy again next year, and, provided AppleTV is smart, Randall will be back for another season of Slow Horses before too long.

With all that said and done, I hope it’s clear just how much I love this show and these characters. Slow Horses Season 6 genuinely might be my favorite season so far, and I can’t wait to see what comes next. The want-to-know-what-comes-next has been compounded by the lack of a next season trailer at the end of the finale. Where is it, Apple? I know you’ve filmed it already! No matter, here’s to 6 more seasons of the best show on TV.