‘I’m Absolutely Thrilled’: Ncuti Gatwa’s Doctor Who Season 2 Casts Slow Horses Star

Slow Horses star Christopher Chung is the newest cast member signing up for Doctor Who Season 2. Chung has been cast as a mysterious character called Cassio.

Chung is perhaps best known for playing hacktivist Roddy Ho in Apple TV+ spy thriller Slow Horses, as well as playing Archie Wong in the BBC’s teen soap Waterloo Road. Doctor Who showrunner Russell T Davies has teased that Cassio could be either a dashing friend or a deceitful foe for The 15th Doctor and his companions.

Christopher Chung is Playing the Mysterious Cassio in Doctor Who season 2

“I’m a huge fan of Slow Horses, and I was so excited to get Chris involved,” the showrunner said “He brings all of his strength and style and talent to one of the darkest, toughest episodes we’ve ever made. As for whether Cassio is an ally or an enemy of the Doctor, you’ll have to wait and see, but I can promise, it’s one hell of a meeting!”

For his part, Chung said in a statement that he is “absolutely thrilled” to be joining Ncuti Gatwa in Doctor Who‘s second season. The show rebranded with Gatwa’s casting, so these new episodes will be Doctor Who‘s 15th overall season since 2005.

“This show is legendary, and getting to be part of this new era feels surreal,” the actor said. “Working with Russell and Ncuti has been a dream! This episode is huge – packed with everything Who fans love: heart, adventure, and a touch of madness. I can’t wait for everyone to see what’s in store—it’s going to be iconic. Get ready.”

“As for whether Cassio is an ally or an enemy of the Doctor, you’ll have to wait and see, but I can promise, it’s one hell of a meeting!”

Gatwa and returning companion actress Millie Gibson (who plays Ruby Sunday) will be joined in Doctor Who season two by Varada Sethu. The actress previously appeared in the season one episode “Boom” playing Anglican Army soldier Mundy Flynn, but will be portraying brand new character Belinda Chandra when she joins the Tardis full time.

Doctor Who Returns Later This Year on Disney+

Ncuti Gatwa Will Reprise His Role as The 15th Doctor in his Second Full Season

Sethu recently confirmed that her two characters are “completely different,” but hinted that there are “gonna be nods” to her dual roles in the Whoniverse.

“There aren’t many shows in the world where, you know, you get to play the same character, but in different times, different planets, completely different circumstances,” Sethu told the Radio Times. “It’s just been wild and so exciting. And I cannot wait for how it all comes out.”

Doctor Who fans can also expect a long-waited showdown between The Fifteenth Doctor and Mrs. Flood, played by EastEnders legend Anita Dobson. Mrs. Flood’s sinister nature played out across season one, where she vowed that The Doctor’s “story ends in absolute terror.”

“I think she realises that things are coming to a head and she really needs to have her wits about her now,” Dobson recently told the Radio Times. “And so she’s beetling around doing what she does, but now with purpose because she knows that the future is holding some kind of finale if you like.”

The actress continued: “So yeah, I think she’s really focused even though she’s ditzy, she’s focused. She knows what’s going on.”

Russell T Davies Lines Up All-Star Group of Writers for Doctor Who

• Current Doctor Who showrunner Davies is confirmed to be joined by acclaimed YA fiction writer Juno Dawson, after the author previously created the podcast Doctor Who: Redacted.
• Pete McTighe returns for a new Doctor Who episode after previously writing season 11’s “Kerblam!” and co-writing “Praxeus” in season 12.
• Inua Ellams and Sharma Angel-Walfall have also joined Doctor Who‘s writing team.

Doctor Who returns for its second season this spring on Disney+ in the U.S., as well as BBC One and the BBC iPlayer in the U.K.