Ah, yes, it’s a regeneration episode!
At its core, each one tries to establish their Doctor, and assure viewers that, yes, it’s still the Doctor. Generally the Doctor has to impress their companion slash audience surrogate while also saving the world (i.e. Earth), or at least that’s how it’s done in New Who, and anyway it’s a tall order for anyone. It’s not necessarily so formula: “The Christmas Invasion” leaves the viewer in suspense until David Tennant comes and solidifies his presence in a single scene, and “The Eleventh Hour” had to introduce all-new companions and present a new “era” of Who.
But needless to say there’s some sort of theme of “identity” in each. Where Capaldi’s intro episode differs is that it is far more focused on that specific theme rather than simply just establishing Twelve, and even sets up a series arc about it (as well as the Doctor’s own ethics). Even the villain of the episode, unlike the standard generic villain to be thwarted, plays into this theme. It’s less “prove yourself the Doctor” and more a slower examination of identity, which may actually play into the episode’s title.
Ah, but how is identity presented? Let us begin…
The opening scene of “Deep Breath” doesn’t directly relate to the whole overarching theme of identity, but does establish some of the Doctor’s own character, which is naturally important and worth noting. Specifically, it establishes him as incredibly alien: talking with a dinosaur, forgetting names, confusing humans and Sontarans. It also demonstrates his own regeneration sickness, with a wobbly camera that keeps on moving around, his general mannerisms (good job, Capaldi), the music in the background, and of course the previous actions mentioned (he also mixes up humans with tiny robot heads). And then he falls over and passes out. The confusion is only heightened by the fact that the episode begins with, with no immediate explanation, a T-rex bumbling around Big Ben, something which tends to raise further questions.
We then get this piece of dialogue:
JENNY: I don’t understand. Who is he? Where’s the Doctor?
CLARA: Right here. That’s him. That’s the Doctor.
VASTRA: Well then, here we go again.
Vastra’s line tends to imply this is a new start, though one of a repeating cycle — it is still, ultimately, the Doctor, if a different incarnation than Eleven. Meanwhile, Jenny’s and Clara’s set up the episode as a whole (right after this the intro credits roll, after all): the question of “who the hell is this guy?” and what it means that he’s “the Doctor”.
Once the Doctor does wake up post-intro things haven’t exactly gotten better. The camera’s still wobbling like crazy, and eventually Vastra basically tricks him into knocking himself out. While he is conscious we do, however, get this easy-to-miss line:
DOCTOR: […] And don’t look in that mirror. It’s absolutely furious.
The motif of the mirror, or the reflection, pops up at least three times in the episode, and this is its first mention. The Doctor describes this mirror as “absolutely furious”, showing how he does yet consider this face “his”. One later scene, with a tramp, will expand on this. The scene also demonstrates a bit of the arrogance of the character, here treated with a bit of comedy (he warns that creating a psychic link will be like “dropping a piano” on Vastra’s mind, and then as he does he is immediately knocked out with a cheesy cartoon sound effect).
Discussing the orderly
Back with Clara, she’s not taking the Doctor’s change in face too well:
CLARA: So what do we do? How do we fix him?
JENNY: Fix him?
CLARA: How do we change him back?
Clara, here, just wants to return him to the appearance she knows him as, the one she likes — until then he’s broken, and not the Doctor. Needless to say, Vastra disapproves, and she makes a strange request to Jenny, and wanders off as mysterious music plays.
VASTRA: Jenny, I will be in my chamber. Would you be kind enough to fetch my veil?
JENNY: Why, are we expecting strangers?
VASTRA: It would seem there’s already one here.
CLARA: What have I done wrong?
Vastra doesn’t actually confirm the Doctor as the “stranger”, but even if it did “seems” implies a certain disregard for that view. She is, instead, probably referring to Clara, who despite having ostensibly such a close relationship with the Doctor is quick enough to reject him upon appearance change. Lecture time soon! Clara’s in no rush, however, and continues to question, despite Jenny’s attempt to change the subject to the dinosaur.
CLARA: Where did he get that face? Why’s it got lines on it? It’s brand new. How can his hair be all grey? He only just got it.
JENNY: It’s still him, ma’am. You saw him change.
CLARA: I know. I do. I, I know that.
CLARA: It’s just
CLARA: Nothing. If. If Vastra changed, if she was different, if she wasn’t the person that you liked?
This constant questioning tone plays into that slow introspective feel of the episode, and is also why I’ve looked at so much dialogue. An irony is presented in how the Doctor’s “brand new” face is so old, though really this is pretty much the most accurate depiction of the Doctor’s age out of all the new Doctors. Clara’s hesistant repetition and and stops show her doubt, in addition to the questioning.
It is then that the Doctor begins reciting the dinosaur’s monologue:
DOCTOR: I am alone. The world which shook at my feet, and the trees and the sky, have gone. And I am alone now. Alone.
CLARA: Are you translating?
DOCTOR: The wind bites now, and the world is grey, and I am alone here. Can’t see me. Doesn’t see me. Can’t see me.
CLARA: Who can’t see it? I think all of London can see it.
The purpose of this is doublefold: in addition to adding sympathy to what is some random dinosaur, it also demonstrates the Doctor’s own confusion and loneliness, being essentially abandoned by Clara.
Continued: (Will put a link here when I’m finished writing part 2, can give no deadlines in this case).