Apple TV+'s Slow Horses has delivered its most gut-wrenching episode yet, and fans are still reeling from the loss of a beloved Slough House agent. In Episode 4, "Lost and Found," the MI5 misfits face their darkest hour as the Russian assassins Jim and Jane close in, and the shocking death of J.K. Coe (Tom Brooke) changes everything.
Brooke, who has played the taciturn and oddly endearing Coe since Season 4, sat down with Collider to unpack the emotional finale of his character's arc, the unscripted moments that made it to screen, and the surprising friendship that defined his time on the show.
An Improvised Reunion with Sid
One of the episode's standout scenes sees Coe, River (Jack Lowden), and Sid (Olivia Cooke) squeezed into a car, with Coe's dry wit on full display. Brooke revealed that the moment Coe offers Sid the front seat—much to River's chagrin—was entirely his own invention.
"I wrote it!" Brooke laughed. "It was a very straightforward scene—get in the car, drive off—and I thought, 'It's too juicy.' Coe's never met Sid, but he knows about her. So I pitched it to Jack and Olivia, and they were all in. Adam [Randall] loved it, and we shot it."
The scene not only highlights Coe's quirky sense of humor but also sets the tone for the trio's uneasy alliance. "Olivia was so great," Brooke added. "She really enjoyed making River sit in the back."
The Bond with Shirley
Beyond the action, Coe's quiet connection with fellow agent Shirley (Aimee Ffion Edwards) has been a subtle thread since Season 4. Brooke explained that the two actors noticed the pattern of them passing guns to each other and decided to lean into it.
"We both noticed that Shirley gives Coe a gun at the end of Season 4, and then he slides her one in Season 5," Brooke said. "So when we started Season 6, I mentioned it, and the writers ran with it. It really helped open Coe up, bring him out of his shell."
That bond culminated in a touching moment at Blake's grave, where Shirley's simple declaration—"I like him"—became a defining beat. "Gary [Oldman] ad-libbed 'Because no one likes him,' and Shirley's response was so perfect," Brooke recalled. "I couldn't help but smile, and I wanted that to be the first and only time we see Coe truly happy."
A Fate Sealed by the Books
Fans of Mick Herron's novels knew Coe's fate was sealed, but the show's version took a different path. Brooke revealed that he was offered three seasons from the start and always knew where the story was heading.
"The ending of Coe was so important that it was one of the first conversations I had with showrunner Will Smith," Brooke said. "I wanted to make sure we did it justice. Every season, I thought, 'This is where we end up.' It was going to be Norway, then Scotland, then a service station in Bakersfield—as is so often the way with filming."
Will Smith explained that the books provide about four of the six episodes, leaving room for new material. "He said, 'We have to find two episodes,'" Brooke added. "So they crafted a version that honors the source material while keeping viewers on their toes."
The result is a devastating twist that will have fans talking for weeks. For more on the fallout, check out our recap of Episode 3 and see how Emma Flyte's demotion set the stage for this tragedy.
As Slow Horses barrels toward its season finale, one thing is certain: Coe's sacrifice will not be forgotten. And for those who love a good spy thriller, this is the kind of storytelling that keeps you on the edge of your seat.
