It's Mary Poppins.

Certainly made me think of a TARDIS control room. Especially the Fountain thing in the middle which seemed reminiscent of the console shape.

Mary Poppins sings.

Heaven is her tardis.

That's Julie Andrews.

I think she'll "collect" his enemies from over series 8?

I think she's the Master. No-one else is that mental!

If that is the case, more fool them to listen to what Missy says.

I was reminded of Suranne Jones' TARDIS too. Wouldn't she class a kind of cyborg? Half machine?

I was also reminded of Teletubby Land so it's fine to gloss over my post.

I see what you mean now. Of course it makes sense the aspect would change just as the Doctor's has and what with the new aspect mimicking his Scottish accent and the 'girlfriend' comment, I think you are spot on.

Ha, ha, very funny!

Maybe she's River Song, but after she's regenerated again, then she somehow "died".

Oooooo like the 5 doctors episode? Doctor will have to figure out how to defeat a collective ammount of bad guys from the entire season

Honestly, I don't know why you lot are wasting your time thinking up possibilities "oh she's the Rani" "definitely a female Master"

Although it's good to speculate, Missy is clearly a brand new character. It would be a new low to bring up a character that's had their story done with. The "my boyfriend" business is something we'll find out in the finale, I think - Moffat's point by that was to make us go "ooh, why is she saying that?" not "ooh, the Rani".

That's actually quite a plausible idea.

At first I thought she was kovarian.

Could she be a somewhat insane version of Romana? back from the other Universe etc? After all, K9 always called her 'mistress' which could be 'Missy'? The other alternative could be she is one of the time lords who could have escaped in the incident at Transalore?

It's the same garden from 'The Girl Who Waited'.

Love Michelle Gomez and seems like this Crack version of Mary Popping is recurring. Knew she'd be in the show at some point from announcement, and it's glad to see they've honoured her innate batshitness.

Also If the Doctor Regenerates, The Tardis also regenerates/changes. Therefore wouldn't Idris change/regenerate aswell? Just a thought...

Confusing the rest of us

People have been getting all hot and bothered about interracial kissing, I'd hate to see what would happen to the internets if The Doctor started a banter with someone and he was having to call her "Mistress" all the time. There'd be bound to be lines about him being submissive, or that he's a slave or something.

If Idris aka the Tardis was the Doctor's wife.....

Missy = the Doctor's girlfriend = Bessie (his car)

Valeyard ?