Slow Horses season 3 episode 6 recap and ending explained

After a bomb went off to end the last episode, Slow Horses season 3 episode 6 continues with an explosive final episode (Slow Horses season 4 is on the way).

The good news from where things left in episode 5, River (Jack Lowden) is alive, but with no other option Louisa (Rosalind Eleazar) arms Sean (Ṣọpẹ́ Dìrísù) to help fight off the Chieftan ops. When he confirms that Ben has died, Sean gets aggressive and is able to push Chieftan back, forcing them to call for reinforcements from Duffy (Chris Reilly).

That still leaves a number of Chieftan ops waiting at it for the Slow Horses, who are making their way toward the hatch unaware of what awaits them. However, as they try to escape, Chieftan's ops in the facility shoot Sean, who is gravely wounded. Just how are they going to get out of this one?

Lamb pulls a Home Alone

Before we dive into that, let's focus on Lamb's (Gary Oldman) rescue attempt of Standish (Saskia Reeves). Lamb sets a number of booby traps to slow down Hobbs (Chris Coghill) and Sturges (Nick Blood), who in his overconfidence gets his arm lit on fire by one of these traps when he busts the door down. More cautious, Hobbs and Sturges search the house.

Roddy (Christopher Chung) arrives at the house to try and help. But when gunfire goes off after Hobbs falls into another trap, Roddy takes cover in an old abandoned double-decker bus. He's able to collect himself though, hot wires the bus and proclaims the calvary on its way.

Back in the house, Sturges notices that Sarah (Eliot Salt) is hiding behind a wall and shoots her, hitting her in the shoulder. Sarah, however, fires back and the two get into a tussle, with her ultimately able to get him into a stranglehold and killing him. 

Hobbs, meanwhile, nears Standish, who is hiding in a closet, but Lamb sneaks up behind him and shoots him in the head. After the enemies are dead, Roddy smashes through the front of the house with the double-decker bus, but his efforts are for naught.

Shootout at the facility

That all happened simultaneously with the facility shootout. Sean convinces River and Louis to take the file, explaining that it'll help prove MI5 murdered Alison to protect their reputation. As for himself, he stays behind and provides them cover fire. While he is able to take out a couple more Chieftan ops, he is ultimately killed, with his last thoughts being of Alison.

Elsewhere, Shirley (Aimee-Ffion Edwards) and Marcus (Kadiff Kirwan) are still pinned down by Chieftan ops. Marcus has Shirley go up a set of stairs to get a better position against them while he provides cover fire. The plan works, but Shirley's gun jams, which the Chieftan ops hear and then chase after her. She is able to trip one up as he runs after her, but the other is right then opens fire, though he misses her and kills his fellow operative. Shirley then manages to knock out the weapons of the other operative, stab him and kill him.

At MI5, Taverner (Kristin Scott Thomas) tells Tearney (Sophie Okonedo) this is going to blow up in her face, but Tearney says she is still confident in Duffy.

Unfortunately, Duffy is not in as control as she thinks. Having already sent two more  Chieftan ops to where Marcus and Shirley are, Duffy gets frustrated and heads that way himself to figure out what is going on. This leaves just two Chieftan ops at the hatch.

Shirley comes back to where Marcus is and gets rid of the Chieftan ops still firing at him. Overhearing on the radio that River and Louisa are about to come out of the hatch, she gets Marcus to give her his car keys so she can help them. Marcus, meanwhile, has to deal with Duffy, who just arrived on the scene.

Now at the hatch, Louisa realizes the trouble they are in when the Chieftan ops start firing. But with more coming up behind them, she and River are trapped. Thankfully, Shirley arrives in the nick of time, kills the operatives at the hatch then, after letting Louisa and River out, drops a grenade on the remaining ones in the facility. After saying thanks for saving their lives, River heads out of the facility with the file.

Marcus, however, is still dealing with Duffy. Duffy gets the jump on him as Marcus realizes he is out of ammo. Duffy chasites him for not counting the rounds in his mag, only to find himself out of ammo as well. This means it all comes down to a fist fight. Marcus is able to get the upper hand and demands that Duffy admit he is beaten. But when Duffy puts out his hand for Marcus, he grabs a knife with his other hand and is about to stab Marcus when Louisa arrives and seemingly kills Duffy with a cinder block to the head.

The aftermath

The situation is no longer contained at the facility, as press and other officials arrive. Taverner officially tells Tearney that she has lost.

On their way back from the Dunn house, Standish talks with Marcus and Shirley. She tells them that they are no longer fired, while they share that River got the file, even though it cost Sean and Ben's lives. Standish, however, thinks what she did was worth it, believing her old boss in the agency, Charles Partner, would approve. But Lamb has had enough of her glorifying Partner. He breaks down and tells her that Partner was a traitor, selling info to the Russians for 10 years. While Standish thought he was great for sticking with her through her drinking problems, Lamb says he did that because her being drunk all the time prevented her from really knowing what was going on. This reveal from Lamb causes Standish to quit.

As for the file, River takes it to his grandfather David (Jonathan Pryce), who reads it over but doesn't see it the same way River does. He believes the file doesn't prove MI5 murdered Alison and all it can do is hurt the agency. When River makes a comment that maybe he sees more of the big picture now than his grandfather (a comment about David's deteriorating mental state), David burns the file, saying it is to protect River. However, River made a copy of the file before seeing his grandfather, which he has in his car.

Lamb meets with Taverner, who is now first desk after Tearney's ousting following River leaking the file. She also reveals that there is a new home secretary (so long Pete Judd). Lamb warns Taverner that everything falls on her now.

Slow Horses season 3 ending explained

A couple of quick answers to pressing questions for Slow Horses season 3 and a quick summation of the Slow Horses season 4 trailer we got at the end of the episode.

We're eagerly awaiting the return of Slow Horses for season 4, but in the meantime, you can watch the first three seasons of Slow Horses right now exclusively on Apple TV Plus.