Doctor Who's Sacha Dhawan promises “emotion and a lot of darkness” from the Master in the series 12 finale

Last seen in this series’ second episode trapped in a strange dimension, Dhawan’s return to Doctor Who had been predicted by many fans, with the theories only increasing when an unknown actor on the episode 10 cast list appeared to have a name that was an anagram of “Master is back".

And chatting to Radio Times magazine ahead of an exclusive series finale interview, Dhawan shed some light on what we could expect from the eagerly-awaited final episode, where apparently his ‘everything changes’ line is pretty crucial…

“I don't want to say too much, but I think my last statement to the Doctor was a really important one,” Dhawan told us.

“And you're going to see more of that and their relationship in the present, in the past... there's a lot to be uncovered. And I think that will bring up a lot of emotion and a lot of darkness.”

So what could ‘change’ for the Doctor? Well, earlier in the series the Master told her that “everything you think you know is a lie,” before revealing that the history of their home planet Gallifrey was built on “the lie of the Timeless Child” – a figure previously mentioned to the Doctor in her travels, and who she has apparently repressed memories about.

Since then we’ve seen this child in visions, while the discovery of an extra incarnation of the Doctor (played by Jo Martin) in the series’ fifth episode hinted that the Doctor is also missing memories of her own life.

So could the Master be about to reveal a terrible secret about both Gallifrey and the Doctor? It certainly sounds like it from the short episode 10 trailer released at the end of the episode.

“I told you before that everything you knew was a lie,” Dhawan’s Master says in the clip.

“Well, now you get to face the truth.”

For now, exactly what that truth is – and how it will change “everything” – remains a mystery. But according to Dhawan, we’re definitely in for a treat when The Timeless Children finally reveals all.

“You know the Master has so many different sides,” he told us. “And you've seen a few of them only in two episodes, but you'll really get to know who this guy is.”

“Also,” he added, “you may have seen in the [Next Time] trailer, I cross paths with the Cybermen. So there's a lot happening.

“It's a very punchy, grand finale to the season, and I really hope people like it.”

If you want to read more, Radio Times’ Doctor Who finale exclusive (featuring interviews with Dhawan and lead cast members Jodie Whittaker, Mandip Gill, Tosin Cole and Bradley Walsh) will be on sale from Tuesday 25th February.

Doctor Who returns on BBC One at 6:50pm on Sunday 1st March