This is not a drill! Apple TV has confirmed that Olivia Cooke will reprise her role as Sid Baker in the hotly anticipated sixth season of Slow Horses. 

The hit espionage thriller, which stars Sir Gary Oldman as Jackson Lamb, the cantankerous leader of a disgraced team of MI5 agents, returns on Wednesday, 16 September. 

A newly released trailer gives fans a glimpse of the gripping new season, which sees Jackson Lamb determined to find out why his spies are being killed off one by one – seemingly by two mysterious attackers played by MyAnna Buring and Kyle Soller.

Olivia’s return was confirmed in the trailer, which ends with River stunned to see Sid at the top of a staircase. 

Sid appeared in the first season of the show but was seemingly killed off after being shot in the head. However, Roddy Ho later discovered that Sid’s records had been mysteriously wiped, hinting at her survival. 

Keep reading to find out all we know about season six so far…

What happens in season six? 

Adapted from Joe Country and Slough House, the sixth and seventh novels in Mick Herron’s CWA Gold Dagger Award-winning Slough House book series, the new season sees the Slow Horses on the run after being targeted by two assailants. 

The official synopsis reads: “In season six, the Slow Horses find themselves on the run as MI5’s Diana Taverner embroils them all in a “fatally high-stakes game of retaliation and revenge,” according to the synopsis.”

Teasing the new season, Christopher Chung, who plays tech wiz Roddy, previously told HELLO!: “I think going into the next season, there’s definitely a lot of crossover from where we left it in season five. Taverner ends up becoming First Desk, is a really fun thing to see play out in season six.” 

Who stars in season six?

Gary Oldman reprises his role as Jackson Lamb, alongside Kristin Scott Thomas, Jack Lowden, Saskia Reeves, Christopher Chung, Aimee-Ffion Edwards, Rosalind Eleazar, Joanna Scanlan, Samuel West, Ruth Bradley, Tom Brooke, Jonathan Pryce and Hugo Weaving.

BAFTA winner Lenny Rush has joined the cast of the series, while Olivia Cooke will return as Sid. 

How to watch Slow Horses season six

Slow Horses premieres on Wednesday, 16 September, with the first episode, followed by one episode weekly until 21 October.