TV fans know Christopher Chung for playing tech specialist Roddy Ho on Slow Horses — he’s at the center of the story in Season 5, with what may have been an attempt on his life already in the premiere, which dropped on Apple TV+ on September 24 — but he also appeared on another well-known series in 2025: Doctor Who.
Chung guest starred in “The Well” as Cassio Palin-Paleen, a trooper who tried going toe-to-toe with the Doctor (Ncuti Gatwa), refusing to listen to his orders and believe his warnings about what was responsible for a series of grisly deaths in a base on a planet.
“It was cold, it was wet. I got to wear a space suit, which was great fun, and I got to work on a show that’s so worldwidely iconic, which I never thought I’d get to do and to work with Russell T Davies was an absolute joy,” Christopher Chung tells TV Insider. “I had a great time doing it. And I got to meet Ncuti. So it’s just fun going into a sci-fi, something completely different to Slow Horses. So, I’ve been really gifted with the roles that I’ve gotten to play in between doing Roddy, but they’re all very varied and different.”
The Doctor soon realized that he had been to the planet before — back when it was made of diamonds. “The Well” was a sequel to “Midnight,” from when Davies was previously showrunner and when David Tennant played the Time Lord.
“When I was auditioning for it, I had watched it. They did send it as a reference,” Chung said of that previous episode. “I didn’t realize how iconic it was, but yeah, when people knew that that episode was going to be a continuation and a follow-up, that was really exciting.”
Cassio’s refusal to listen to the Doctor did ultimately result in his death. He took control from his leader, Shaya (Caoilfhionn Dunne), declaring a red code, for an incompetent leader, and his actions eventually led to Shaya putting him directly behind Aliss (Rose Ayling-Ellis), to whom the entity had attached itself. Those who ended up in that position, at “midnight,” were killed. She explained that she had to because he was out of control. “It’s what it turns us into,” the Doctor said.
Doctor Who, Streaming Now, Disney+