Slow Horses season 6: all the burning questions we need answering

Slow Horses fans, look alive! After Apple TV confirmed the return of season six and teased the surprise return of more than a few forgotten faces, we’ve collated all the burning questions we need answering for the next instalment. 

Warning: this article contains spoilers for season five of Slow Horses, so make sure you’re up to date before you keep reading.

After Apple TV released the trailer for Slow Horses season six, it’s safe to say we’ve all been left well and truly shocked and in serious need of some answers.

The new instalment, which returns this September, follows the sixth and seventh novels in Mick Herron’s book series and reunites viewers with the dysfunctional yet loveable rogues that occupy the British intelligence dumping ground that is Slough House. 

Starring Gary Oldman, who plays the brilliant but repulsive Jackson Lamb, the head of Slough House, the new season sees the Slow Horses on the run as the newly promoted Diana Taverner (Kristin Scott Thomas) embroils them all in a fatally high-stakes game of retaliation and revenge.

And while the recurring cast – including Jack Lowden, Saskia Reeves, Christopher Chung, Aimee-Ffion Edwards, Rosalind Eleazar, Joanna Scanlan and Jonathan Pryce – all reprise their roles, there was one face in the trailer that led us all to do a cartoon double-take: the return and apparent resurrection of Sidonie ‘Sid’ Bake, played by Olivia Cooke.

So if, like us, you’re still reeling, we’ve collated all the burning questions we desperately need answering for the new season, which lands on 16 September. 

The trailer kickstarts with Lamb back causing havoc once again – this time, breaking into Taverner’s back garden to demand why his Slow Horses keep turning up dead. Despite dismissing it as a coincidence, Lamb says: “Coincidence, yeah. But it’s pretty hard to lock yourself in a shipping container.”

The clip then pans to a man and a woman setting said shipping container alight – so who are they and why are they targeting Lamb’s team? Has Taverener, as Lamb puts it, “pissed anyone off other than him recently”? And does it have anything to do with right-wing politician Peter Judd (Samuel West), whom Taverner directs her steely gaze at over a restaurant table?

This isn’t the first time the team have been targeted by unknown enemies over the multiple series. But this time, it looks like there are a series of people caught off guard, like Moira Tregorian (Joanna Scanlan), who becomes the subject of a mysterious gas attack. Will Lamb be able to gather the troops and get them to a safe house before more are targeted?

As for those enlisted to retreat to a safe house, the trailer shows the gang turning up at Louisa’s (Rosalind Eleazar) place of work. After last season saw her step away from Slough House after a mental health break, she tells them: “I haven’t been in touch for months, I’m not actually needed.” To which Standish replies: “No, I’m afraid you are.”

What will happen when Louisa reunites with the team, especially after she shared that awkward kiss with River before her departure at the beginning of season five?

While River’s father, former CIA mercenary Frank Harkness (Hugo Weaving), managed to weasel his way out of apprehension after he blackmailed MI5 in season four, it seems he may be back again as the trailer sees him go nose-to-nose with his estranged son.

“What are you doing here?” River demands. 

“Business,” Frank replies, before the camera pans to Frank trying to murder someone in a complicated tussle. What’s the motivation behind Frank’s return and will it be to the help or hindrance of his son?

After season five ended with the removal of Claude Whelan (James Callis) from MI5, Taverner is finally where she’s always wanted to be: sat in First Desk – but is she really up to the task? In the trailer, we see her sitting at a hearing, where she’s told: “No one is unaccountable, Diana. There are going to be consequences.”

Catching heat from officials, as well as Lamb and Emma Flyte (Ruth Bradley), just how far will Tavener really go to save face? 

As for that final trailer bombshell, we see Sid standing at the top of the stairs, smiling down as she says: “Hello, River.” As fans may recall, Sid seemingly perished from a shot to the head by a masked assailant in season one after following far-right journalist Robert Hobden (Paul Hilton) and mysteriously disappearing – declared dead by Taverner, who claimed she had died from her injuries.

So, what really happened to Sid that night? Was she shot in the first place, and if so – and she survived her injuries – why did Taverner confirm her death? 

One of the most revealing snippets from season five was when Lamb told his team a story as they’re locked down by the Dogs. He told them about an apparent ‘Joe’ of his who was tortured by the Stasi to the point where his feet were burnt off. To motivate him, the Stasi brought in his pregnant lover, whom they tortured and eventually murdered when he didn’t give up the information they thought he had.

While the story seemed a way to motivate River to use his own aerosol can to escape the Dogs, the season ended by showing Lamb’s own scar-ridden feet, implying that he was the subject of the harrowing story. So, who was this woman and what more will we learn about Lamb’s past in season six? Consider us well and truly intrigued as we count down until its premiere. 

The first episode of Slow Horses season six lands on Apple TV on Wednesday 16 September, and will be followed by weekly episodes every Wednesday after.