After a bit of an absence Doctor Who star Michelle Gomez is returning to the sci-fi series in tonight’s episode Extremis, with the Scottish actress (who plays a female incarnation of longstanding Time Lord villain The Master) keen to resume the part that’s been a hit with viewers since she first debuted in 2014.

“It’s always amazing, because it’s just such a fun role, and it’s such a great cast of people,” Gomez told RadioTimes.com. “Yeah, it’s really…it’s good. You can quote me on that – ‘it’s really good.’

“It does blow me away that I’ve got more than one fan, and that’s my mum. And I’m still in a state of humbled gratitude towards that. That Missy as the Master being the first female Master was so wholeheartedly accepted. And that’s not lost on me, I’m very grateful for that.”

With that said, things have changed a bit since Missy’s last appearance – longstanding companion Jenna Coleman has gone and newbie Pearl Mackie is now at the Doctor’s side, with Matt Lucas’ valet Nardole also joining the Tardis team this series. So how will Missy react to Bill and the other new faces?

“I think the usual Missy reaction – just sort of some other little toy to play with and then cast aside,” Gomez said. “I don’t think she actually really sees Bill to be honest – she sort of moves past the companion pretty swiftly and gets to the Doctor as quickly as possible.

“I mean it is different,” she added more seriously. “It’s always good to have a new, fresh, energy. But you know, obviously the dynamic with Missy and Clara last year, it was almost like a double act.

“Which was kind of bizarre, you didn’t really see that coming. Cos Jenna Coleman is actually an extremely funny woman indeed. And so we really enjoyed that.

“Whereas this year, you know Pearl’s completely different energy, which was really exciting to work with also. It’s always good to embrace a new energy. So you’ll see – it’s different. But of course it’s different, she’s a completely different person playing it.

“And then obviously there’s Matt [Lucas] as well, that comes into it. I think Matt and Pearl are more of the double act this year.”

Of course, as much as fans will be excited to see Missy bouncing off the Doctor’s new pals, the real excitement is expected later in the series, when the Time Lady will team up with her previous incarnation (played by a returning John Simm, last seen in a 2009 episode of the series) for the two-part finale in a dark twist on the programme’s trademark multi-Doctor episodes.

Michelle Gomez as Missy and John Simm as The Master

“Well, you’re going to find out that everything that happens is all a bit odd,” Gomez said of the upcoming team-up. “And it’s all about the shock yes, and it’s all about the shock.”

But perhaps keen to preserve that shock, Gomez was cagey about other details of the pair’s appearances together, deflecting when asked what the reaction was when Simm’s Master saw her female incarnation.

“Oh I don’t know, you’d have to ask him,” she told us. “It’s his reaction, not mine. Ask John.”

When asked how Missy herself reacts, she added gnomically: “Erm…it was exciting?”

Still, the former Green Wing star could be enticed into talking about the acting challenge present in two Masters sharing the screen, promising that her famously off-the-wall interpretation will be even weirder this time around.

“I think the dynamic with the fact that there’s two Masters in one brings a sort of weirdness that even I didn’t think I could reach,” she laughed.

Michelle Gomez in the new series of Doctor Who

“And it really was like John and I were presented with an acting challenge which was really exciting. Because you think you know a character and you think you know a job because you’ve been doing it for three years, and then it’s completely up-ended and is changed beyond recognition.

“And that brings with it change. And I think it’s good – I think change is good. I don’t think we can ever when we’re in the realm of telling stories, stay in the same place. I think there’s always something new to say.”

Though of course through all the new faces, returning villains and exciting new storylines there’s one thing that definitely hasn’t changed – Missy’s complex relationship with Peter Capaldi’s Doctor, which is caught somewhere between bitter foes and best friends.

“It’s a friendship that’s gone wrong over time,” Gomez mused of the pair’s relationship. “But I think they’re still happy to see one another, and then within five minutes of each other’s company they remember why they deleted them in the first place.”

It is, however, also a relationship that’s swiftly coming to an end.  You see, this series will mark Gomez’ last time playing Missy, with the actress revealing to RadioTimes.com earlier this week that she’d decided to leave due to the approaching departure of Capaldi and head writer Steven Moffat.

“My pals are going so I’m going,” Gomez told us. “Everybody’s leaving, so I’m going too. I mean, what would I do without Peter and Steven? Who would I be?

“Nah, it’s done now. It’s over. It’s the end of a chapter.”

Michelle Gomez in tonight’s episode of Doctor Who

And while she said she had no regrets about her decision, she admitted she’d always feel a certain nostalgia for the series that gave her the role of a lifetime.

“[I’ll miss] the fact that it was probably one of the best jobs I’ve ever had,” she said. “The fact that I’m a woman of a certain age who’s this ass-kicking action figure.

“I won’t miss the corset because that was agony, and I’m a woman that likes a big lunch. And that’s not fun to wear after you’ve had two helpings and dessert.

“So I won’t miss that. But I’ll miss the amazing, wonderful, incredible Peter Capaldi, who I think is one of the best Doctors we’ve ever had. I’ll miss somebody like Steven Moffat writing me the best lines I’ve ever had in my career.

“I won’t miss the rain in Wales, but I will miss Wales. And the incredible crew that work so hard. It’s not work for them, it’s a passion, and that’s wonderful to be surrounded by. It’s very inspiring and energising.

“Yeah, I’m gonna miss a lot about that job,” she concluded. “It was a great job.”

Michelle Gomez will return to tonight’s Doctor Who episode Extremis.