©BBC/BBC Worldwide 2014

The first part of the "Doctor Who" series eight finale, "Dark Water," which aired November 1 on BBC America, was a rollercoaster ride. Not least of which that we finally found out more about Missy (Michelle Gomez), the mysterious antagonist who has been subtly manipulating The Doctor (Peter Capaldi) and Clara (Jenna Coleman) all series long.

To find out more about how the epic first half of the finale was put together, MTV News caught up with Gomez over the phone - as well as director Rachel Talalay, who helmed both "Dark Water" and next week's "Death In Heaven." Read our interview with Talalay, here!

Spoilers for "Dark Water" past this point!

MTV: When did you first hear that you got the part of Missy? How did you end up locking that down?

Michelle Gomez: I got an offer to join earlier in the series, which I couldn’t physically do because I was working on another show called "Psychobitches." It’s about psychotic women in history. It’s very funny, you should check it out… It’s coming out at the end of the month.

Anyway, so I thought, "Oh my god! I’ve lost my ticket to 'Doctor Who!' I’ll never be asked again!" So I wrote a letter to the very wonderful, incredible genius that is Steven Moffat saying, "I’m terribly sorry. You know, I can’t be in 2 places at once because I don’t have a TARDIS, but if there is any possibility in the future, the I’m available for witches and bitches because that’s what I’m destined to play."

Didn’t hear anything and then two weeks later, I got an incredibly nice one-liner from Steven saying,

Can you say no to this?" And sent me this version of events, which I of course grabbed with both hands and thankfully I was free and here we are today!

Adrian Rogers, ©BBC/BBC Worldwide 2014

MTV: So did you go out for a different character than Missy, or did they just juggle it a little bit to make it work for your schedule?

Gomez: Yeah I was asked to do something else and then I couldn’t, so they did this.

MTV: Could you tell us about what else you went in for?

Gomez: No, that’s been and gone. I can’t even remember what it was.

MTV: Fair enough... I've been curious about how you filmed the part, other than for the finale. You've been credited for some episodes, uncredited for others. Did it all happen in one chunk, or have they been bringing you in on a weekly basis? It's certainly far more than fans were expecting.

Gomez: Yeah there was lot’s of it. My character had a block of filming, so they basically just compressed everything that Missy needed to do into one big, fat chunk and we just filmed it out that way.

MTV: Of course they’re very secretive on the show... Do they just hand you a scene and say, "Okay and now you’re going to smile a little bit here, but we can’t tell you what it is," or did you know what was going on with Missy the whole time?

Gomez: Well, luckily I never really know what’s going anyway with anything that I do, so I was perfectly cast for this. Like most British actors, I tend to sort of get onto it and go, and I don’t ask too many questions. [I] pull a few faces and don’t embarrass myself... And that’s seems to have worked out very well.

Adrian Rogers, ©BBC/BBC Worldwide 2014

MTV: So who is Missy, inside? In "Dark Water" we see her go through not just a bevy of emotions, but pretend to be different types of characters, as well.

Gomez: I think that she is the sum of all human emotion. She's a miraculous weather system in her own right, and I framed her almost I guess schizophrenic in a way... She can shift from a thunderous, terrifying presence, to at times a little girl. So yeah, I suppose she is the sum of all human emotion in just one droplet.

MTV: Over the course of this season we’ve seen this new Doctor struggle with his humanity - or his lack of humanity... And all the best villains are, of course, a parallel or opposite for the hero. So is that what's going on here? Are we getting through Missy what the Doctor has been lacking?

Gomez: Yes! Some people in our lives somehow mirror who we really are, and they are not mirroring the mask that we put on to meet and greet on a daily basis. For a man such as The Doctor, he has this kind of conscience now, asking the bigger questions of, "who am I really?"

We all arrive at that point in our lives, and whether we can really with rigorous honesty find answers that can sit well... There will be demons there that perhaps he hasn’t dealt with, or he’s repressed or he doesn’t feel good about.

Missy just blazes that light on all of the defects of his character. There's that wonderful feeling you cant bulls--t a bullsh--ter. It's almost that type of relationship with them of a sibling, or any close friend of yours that knows who you really are at your core... And is able to turn up, and remind you who you really are behind that mask. Missy is his barometer conscience that turns up.

Adrian Rogers, ©BBC/BBC Worldwide 2014

MTV: Can we talk about you and Peter's kiss in the episode? It's so funny - particularly those last three little pecks on his nose at the end... How'd that come about?

Gomez: Well you put two Scots in a room together and there's going to be some nonsense. Peter and I are both from Scotland. We're both from the same town, so there was a little improvising here and there. We were very relaxed with each other, and very free and easy - which means you get these little moments that are not scripted, but they just sort of happen on the day. That was Peter and I having our Scot off

MTV: Though they teased it in the press pics, the Cybermen showing up at the end of the episode is paced so incredibly... As a fan of the show, what was it like being on set with them?

Gomez: Well, that probably was up there with my wedding day! It was one of the most incredible, magical days of my life - really. I’ve been knocking around in this business for 20 odd years, and it doesn’t get any better than that. I would describe it as pure magic actually. It was very very special. Very special.

MTV: There was so much speculation about who Missy was, and we finally get to find out what she's up to in this episode - and that, in fact, she's The Doctor's arch-enemy The Master... Was there any other guess in particular you enjoyed?

Gomez: I love that Mary Poppins is possibly the most evil woman in the universe! That tickled me. Because now I'm not sure whether that is a theory, or a fact. I like that.

Adrian Rogers, ©BBC/BBC Worldwide 2014

MTV: What was it like working with Rachel Talalay on set for this and the next episode? Not that the season has been too shabby, but "Dark Water" was a particularly beautiful and emotionally textured episode.

Related: 'Doctor Who' Director Reveals How They Pulled Off The Ambitious 'Dark Water'

Gomez: She’s amazing. She's kind of spoiled it for the rest of my working days. I only want to work with Rachel Talalay, and she's just wonderful. She creates a kind of an incredible atmosphere on set, one that feels safe and comfortable. She brings out the best in everyone, from every department, and I just knew I was in good hands from the moment I met her. Shes a very special person indeed, and if she asked me to go open a packet of crisps for her – I would do it

MTV: Before we let you go, what can you tease about the season finale?

Gomez: Oh, just watch it, it's very good. You wont be disappointed - and nothing that you think is happening is happening... Nothing.

What did you think about all the big reveals in "Dark Water?" Let us know in the comments below!