He's back! Sacha Dhawan's Master made his triumphant return in the final minute of Sunday's episode of Doctor Who, crashing through what seemed like a boundary between universes but turned out to be a portal to Gallifrey. As the Master put it, "That's a good entrance, right?"

The Doctor's (Jodie Whittaker) "best enemy," who had been trapped in the Kasaavin realm since the end of the two-part season premiere, picked an appropriately chaotic time to jump back into the fray. The Doctor and her fam are busy trying to stop the Lone Cyberman, Ashad (Patrick O'Kane), from wiping out the last of humanity and rebuilding the Cyber race — not exactly the ideal time for a history lesson on the Time Lords' many offenses. But the Master has been trying to tell the Doctor something about the "Timeless Child," a secret so shattering it led him to destroy Gallifrey, since the season premiere, and it looks like it's time for that secret to come out.

While we wait for the Master's next move, TV Guide spoke with Sacha Dhawan about the emotional season finale ahead, how he and Whittaker embrace their characters' unpredictable dynamic, and one surprising inspiration for his character.

At the end of Sunday's episode, the Master told the Doctor, "Everything is about to change." What can you tease about what the Master means by that?
Sacha Dhawan:
It relates to the statement that I said to the Doctor at the end of Episode 1, which was, "Everything that you think you know is a lie." So I'm planting these small seeds which will hopefully be resolved in Episode 10. But as with Doctor Who, more answers lead to more questions... You're going to see a different side to the Master [in the season finale], as well as a different side to the Doctor. You know, it's action-packed, and it's chaotic, but at the same time, there's real heart there and a lot of emotion which will be uncovered.

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At what point in the season did you find out what the Master is so upset about? Did you just learn it when you got the finale script, or did you know since the beginning of the season?
Dhawan:
I think the script was still being evolved, because I came in Episodes 1 and 2, and obviously 9 and 10 were still being drafted. I spoke to Chris [Chibnall, the showrunner] probably a month or so after Episodes 1 and 2. He'd asked me to come back for 9 and 10, and we had a conversation about it, and I won't lie, initially I was like, "Oh my god. This is amazing." I felt immensely proud to be part of the storyline, but also really scared as well. Both Jodie and I were. But we had a real big conversation about it, and from that conversation I felt like the Master evolved even more. And I love that about the character. There's so many different sides to him and different personalities. And that's one of the things Chris said to me, actually, is, "You don't have to reveal him all at once." Yes, there is a reveal at the end of Episode 1. But the character will always continue to evolve, and in a way that made him much more unpredictable.

Could you speak more to what that process was like, figuring out your Master's personality and what makes him tick?
Dhawan:
A lot of people were like, "Did you look at previous portrayals of character?" And Chris advised me, and I wanted to as well, not to look too much at things that had been done in the past. Obviously take some of the important facts, but it would make it much more interesting for me to kind of put my own stamp on [the character]. What I needed from Chris, which he did, and Matt [Strevens], the executive producer, was to give me the blessing to make it my own. And what was really exciting was the constant conversations I had with Chris... It felt very collaborative. He provided a lot of information, but one of the things we discussed that I brought to the table was the chaos theory: the idea that by creating loads of chaos, amazing things can happen — well, from the Master's point of view. I didn't want to feel that he was just being fun and playful for the sake of it. There was a real method to his madness, if that makes sense. So in one sense, people are going to be like, "Oh, he's just kind of playful and silly." And then on the flip, you'll go, "Oh, actually, this guy is very tortured, and has something up his sleeve all the time." I think one of the things I really wanted to do with my portrayal of the role was to make him much more unpredictable, more emotional, and a lot darker, which again, you'll see more of in Episode 10.

Sacha Dhawan, <em>Doctor Who</em>Sacha Dhawan, Doctor Who


You and Jodie Whittaker have such strong onscreen chemistry. What was the process like for the two of you in terms of figuring out the dynamic between your characters?
Dhawan:
I think it's a credit to Chris and Matt, really. Honestly, they just put us together... As soon as me and Jodie worked together, it was just really easy. I'd worked with her before, anyway, a few years ago, but not on this level. And I don't think me and Jodie knew, especially in 9 and 10, the journey that we were going to go on together. What I really respect about Jodie is she lets you do your job to the best of your ability, because when I play the Master, he is very different to me, and when I'm on set I like to be a bit unpredictable at times. And she really embraces that and goes with it. She's never like, "I don't know what you're doing." And what she'll do is take it and go with it and throw it back at you, and it just makes the relationship really exciting. It's a relationship I don't think we've quite seen before. It's a real joy to play.

There has been some debate about whether your Master is a regeneration after Missy, or whether maybe he's from earlier in the Master's timeline. Can you speak to that at all? Is that a conversation that you had with Chris at any point in the season?
Dhawan:
I've read some of the responses, and it's an interesting question to ask. But when I first got the part, it was amazing that Chris wasn't like, "You've got to remember this, remember that [about the Master]." It was actually completely opposite. He was like, "Make it your own. Don't get too bogged down by the history." And in a way, by doing that, it freed me completely, and it allowed me to have my own individuality when it came to the role. So there wasn't really any discussion about previous incarnations, which I really liked.

I wanted to touch on the scene in Episode 2, "Skyfall, Part Two," where the Doctor removed the perception filter around the Master so that the Nazis would see his true face. There was some backlash to that scene, and some people thought the Doctor went too far there. I was wondering if you had any thoughts on that scene.
Dhawan
: I guess it was quite controversial, but I enjoyed the challenge of playing the character as a British Indian actor, dressed up in that type of costume. It felt really brave of Doctor Who to do that in this setting. And you know, there wasn't really any discussions about the perception filter. It was more so that once you remove the perception filter, that my fellow colleagues are going to reveal that I'm not who I said I am. I think that's what it was in the story. But for me to be playing that kind of part, I think it flipped casting on its head a little bit. Which I'm quite proud of.

Sacha Dhawan, <em>Doctor Who</em>Sacha Dhawan, Doctor Who


After the premiere, you shared an Instagram post about the anxiety you were dealing with when you took on this part and how the cast welcomed you. What has the response been like to that?
Dhawan:
Well, the anxiety was not anxiety just about the role; it was something that I felt that I'd carried for a couple of years. And I've never really been vocal about it — as a lot of people are. They're not vocal about how they feel or their mental health, particularly men. For me, I kind of battled with a bit of anxiety. In one sense, when I was in front of the camera or on set, people would not think anything different, but then I'd go back to my trailer, and I'd doubt myself. I'd think, you know, "I'm not good enough," and I just wouldn't let the feeling go. And it led to me going, "I just need to take some time out and figure out what this is and maybe speak to somebody," which I was quite embarrassed about, to be honest. I didn't really speak to anyone about it. I took some time out, and then as life has it, you're kind of on your resting period and you get the call for a role that is life-changing, and obviously you can't say no. So that's where the anxiety increased, because I was like, "I'm not sure if I'm going to be able to do this, and honestly, I don't want to open up to Matt and Chris about this, and they might retract the role, you never know."

But actually, it did the complete opposite. It got me to confront my anxiety, as I was slowly starting to do anyway... [Fans] see the end result, but what they don't see is what happens behind the scenes. The whole cast and crew are the most supportive team I've ever worked with. And you can see that in my performance. I wouldn't have been able to be as unpredictable or have the confidence to do that type of character if it wasn't for them. So I guess I've decided to be more vocal about mental health in the hope that it will encourage others, particularly men, to not sit in silence and to talk about it and get help.

And can you say anything about whether we'll see your Master past this season?
Dhawan:
In all honesty, I haven't been asked yet. [Laughs] So you know, I'd love to. I'm just really happy and honored that the fans are happy with my incarnation of the role, and if I was to come back, then great. If not, then I'm really happy that I got to be in this season and work with the first-ever female Doctor. That's enough for me.

The Season 12 finale of Doctor Who airs Sunday at 8/7c on BBC America.