*Warning - contains spoilers for Slow Horses season 6 episode 2.*
Back in August, Slow Horses fans got a big, welcome surprise, when it was announced that Olivia Cooke would be returning as Sidonie 'Sid' Baker in season 6.
The character hadn't been seen since she was shot in the head in season 2. At the end of that season, Roddy Ho (Christopher Chung) intimated that she could be alive somewhere, but nothing has been heard since regarding her whereabouts.
Now, the second episode of season 6 has been released, and it ended with Sid's return, appearing at the top of the stairs in River's (Jack Lowden) grandfather, the late David Cartwright's (Jonathan Pryce) house. River had thought his villainous father Frank, played by Hugo Weaving, would be there, but was shocked to see Sid instead.
"It was an absolute treat that we got to do that, because she was so good in season 1, but in it so briefly," director Adam Randall said of Cooke's return, when speaking with Radio Times. "And I thought that [Cooke and Lowden's] chemistry in those two episodes was just fantastic.
"So the reveal was hugely fun. We obviously build up this whole idea that, ‘Where's Frank? Frank's calling him. Frank's in the house.’ And then the surprise that it's her."
Randall admitted that this reveal was originally supposed to be a bigger surprise, and that "we didn't know it was going to be in the trailer until I saw the first cut of the trailer".
"I understand why it's in the trailer, and there's a lot of excitement around that, which is completely fair enough," he added. "It was going to be kind of thrilling for that to have been revealed in the second week of it coming out."
Randall also teased a romantic storyline for River and Sid, after their connection in season 1.
"I think it just adds something very, very different to the show," he said. "I think the show doesn't really do romance in a way, and I think it just brings a huge beating heart to this season, especially a season where there's a lot of darkness."
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Sid isn't the first returning character from season 1 to have popped up.
The first episode also saw the brief reappearance of Paul Higgins as Struan Loy, although his character was swiftly killed off by the chilling pair of assassins, Jim (Kyle Soller) and Jane (MyAnna Buring).
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