‘Slow Horses’ Season 4 Theories And Predictions: What To Expect Next From Apple TV Series?


The successful spy thriller AppleTV+ series Slow Horses has ended its third season with an equally good presentation as before, with a conflict within MI5 over a secret and classified file at the center of this year’s events. Slow Horses Season 3 features an internal strife between the MI5 First and Second Desks, Ingrid Tearney and Diana Taverner, respectively, and this is what takes precedence in the plot this time. Wanting to take Tearney’s position, Taverner had hired a particular ex-spy named Sean Donovan, who wanted to take revenge against the MI5 for having killed his lover Alison Dunn. This murder was over a particular confidential file, codenamed Footprint, which noted how Tearney was responsible for the deaths and serious injuries of a number of civilians and other spies. Therefore, Taverner used Donovan to get hold of this Footprint file, and at the end of the season, Ingrid Tearney is indeed ousted, while Diana Taverner becomes the new MI5 Director General.

Spoiler Alert

What will be the main issue in season 4?

Just like in every other season before, the last episode of Slow Horses season 3 also presents a brief teaser for season 4, which seems to be an equally thrilling iteration with some seriously high stakes. The main conflict in each of the seasons so far has been very interesting. Slow Horses Season 1 featured a conservative group named the Sons of Albion rebelling against authorities, as they were being used for political reasons, and so the Slough House agents had to uncover the real truth. Season 2 had secrets from the Cold War era being brought back to haunt MI5, as Cicadas, or a network of foreign Russian spies, emerged to be very real threats. Season 3 now shows how the MI5 higher-ups have been using the spies and rejects from the lower rungs of the service to get their personal aspirations fulfilled.

In each of the three seasons, there has been a point in time when the Slough House members have been tracked down or pursued by MI5, for they have decided to act against higher orders. Since Slough House is essentially for spies who have been rejected from service at the main organization, they do not always face the same tracking or surveillance that the other agents do. This, and the fact that the most spies from Slough House have a penchant for heroics, have made them always go against orders in the past. Season 3 is a great example of this, as River and even Catherine give the rogue Tiger team their support after they ultimately realize how the service has been unjustly hurting people.

Going by the teaser for Slow Horses season 4, the main issue or problem at the center of the next iteration seems to be a more general and outward one. Instead of any internal conflict or violent competition, a moment of emergency is created when someone threatens to set off a devastating bomb in the city of London. The reason for this threat is not known yet, of course, but the scale of danger that it poses is quite apparent, for the MI5 appoints swarms of combatants to deal with the situation. Lamb is heard reminding Taverner how the explosion of a bomb in London would harm the reputation of MI5, since the intelligence service holds responsibility for all matters of internal safety in the country.

Diana Taverner is also seen launching an investigation into how many perpetrators are exactly involved, for there is a possibility that a second bomber is also making an equally devastating plan. The whole matter can be the work of a group that might be targeting civilians or the authorities for some specific reason, like the Tiger team in season 3. However, it is also possible that if there are multiple bombers, they might not be related to each other and yet be inspired or driven by each other to unleash their vengeance on the city. But it is evident that the matter also includes some secret about the MI5, possibly some undisclosed internal incidents from the past, for Taverner claims that they must stop some information regarding this from leaking to the public. 

What other conflicts can be expected?

Along with the main storyline, Slow Horses season 4 will also definitely feature some other side stories, which will all tie in with the main plot by the end. This has been the style of the AppleTV series, and that can be expected to continue. Firstly, along with a new Director General of the MI5, Diana Taverner, there is also a new Home Secretary in place, since Peter Judd has been exposed as a co-conspirator in the scandalous events of season 3 and, therefore, has been removed from the position. Whether we might still see Tearney and Judd, though, is a different matter, for they can make some appearance if they are not imprisoned. However, Slow Horses also does not typically carry forward too much of a season’s issues into the next season, so the two being seen again seems unlikely. However, talking of returning characters, Catherine Standish will definitely be a part of the season, despite having left her job at Slough House at the end of season 3, a decision that still stands. This year’s show also had Shirley Dander and Marcus Longridge being unsure about whether they still have the job as Slough House agents, but the teaser seemingly confirms that they are indeed still spies at the service.

We can surely expect some continuing political drama, as Diana Taverner will have to fit in with the new Home Secretary as well. It has been made clear by the series so far that these political understandings and allegiances are not made very easily, and they generally require some twisted plan with some collateral damage. Whether this political strain will have any effect on the bombing plot, or whether the latter even exists because of the first, remains to be seen. But it would be most likely that the perpetrator, or multiple perpetrators, have some vengeful ideas against the authority.

 There indeed seems to be more than one perpetrator, as the main antagonist seems to be played by Hugo Weaving. The man is seen trying to convince MI5 agents to work for him, or at least let him do his work without creating any trouble. He is also seen threatening Molly Doran, who is the official records keeper at the Regent’s Park headquarters archive. Molly’s fate is indeed unclear, for she might get killed by Weaving’s character. But the exact reason for attacking the recordkeeper is a mystery that will be solved only when the new season comes.

Jackson Lamb is seen breaking into some offices on his way to investigate the bomb plot, in all probability. River’s background narration sets up a very important role for Lamb in the new season, as he is claimed to be almost unbeatable as a spy when he is not lazing around and is actually doing some work. The man is still as insensitive about his agents as he has always been, as he refers to them as outright rejects to a young woman who seems to be interviewing him. At the very end of the teaser, Lamb also very casually states how an agent of his has just died, meaning that someone from Slough House will face their end in Slow Horses season 4. The death of Min Harper back in season 2 has Louisa still affected by the loss, and whether the death of this particular agent will have any similar effect on anyone else will be interesting to see.

Lastly, we also see David Cartwright, but there is something odd about him, as the elderly man calls out to River, who seems to be hiding from him. River went against the wishes of his grandfather at the end of season 3 and leaked the Footprint file, despite the ex-MI5 officer not wanting him to do so. This can create some animosity between the two characters, but their familial tie will also not let things get out of hand. David Cartwright’s failing memory and perhaps other senses might pose a bigger problem in the new season, and he too might be targeted by the perpetrators because of his vast knowledge of MI5 history. If someone is particularly out for revenge against some previous incident, then David Cartwright being the target of an attack seems all the more likely. In that case, it is possible that someone else might have broken into David’s house, posing to be his grandson, River. Overall, Slow Horses season 4 already looks like a very interesting prospect, and it would be thrilling to watch when it finally comes.

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Sourya Sur Roy
Sourya Sur Roy
Sourya keeps an avid interest in all sorts of films, history, sports, videogames and everything related to New Media. Holding a Master of Arts degree in Film Studies, he is currently working as a teacher of Film Studies at a private school and also remotely as a Research Assistant and Translator on a postdoctoral project at UdK Berlin.

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