Spoilers for Doctor Who - 'Deep Breath'
Where to start? Capaldi of course. He's charismatic even when saddled with extended post-regeneration whackiness (the bedrooom scene is hilarious), and convincing as the Doctor from around the restaurant scene onwards. There's a conscious - perhaps overly self-conscious - shift towards making the Doctor a spikier figure. Although the word 'darker' is not entirely inappropriate - of which more in a minute - it's truer to say that he's more grown-up. There's a depth behind the eyes and a capricious intelligence that makes him marvellously unpredictable. Although we never doubt that he'll return for Clara, or truly feel that he'll cut-and-run in a crisis, the fact that he will disappear to pursue his own course of action lends him an unsettling pragmatism.
It's that pragmatism that is really meant when people talk about 'darkness'. He's not 'dark' most of the time. He's cheerfully rude, with some snappy humour. But that pragmatic streak is what leaves room for doubt as to whether he pushes the half-faced droid, whether he's lying about his 'programming'.
I'm no fan of the Doctor being a killer. It sat poorly in 'Dinosaurs on a Spaceship' and 'A Town Called Mercy', and 'The Day of the Doctor' re-cast such moments as a character arc, the Doctor losing his sense of self only to regain it in his 50th anniversary, the whole point of which is that the ends cannot justify the means. It seems peculiar therefore to immediately return to that well of moral ambiguity. It implicitly concedes that the ideologically pure pacifist hero is unrealistic to a modern audience, that either the writer can't conceive of ways to resolve the plot without recourse to violence, or that the audience won't believe the bait-and-switch required to sidestep the seeming inevitability of violence. For the Doctor to act as if the ends justify the means flies in the face of the entire ethos of the series. It's not that the character has never pondered these questions, and indeed from Davison's agonised attempt to assassinate Davros in 'Resurrection of the Daleks', through McCoy's manipulative long game, to Tennant's stony "No second chances" in 'The Christmas Invasion' you can see a hardening in the way the character has approached pragmatic violence. Maybe those who loved the Doctor in his New Adventures era may feel that this alien ruthlessness is just a part of the enigma of the character (I never read the novels, but the on-screen character derived from them at the end of 'The Family of Blood' feels imported from somewhere else entirely to me). I think it's very difficult for the character to fully embrace violent solutions without undercutting what makes him appealing. There are enough sociopathic heroes on our screens, and too few idealists.
The wiggle room that the series increasingly uses to excuse this behaviour is the "no second chances" mantra: the Doctor only resorts to ruthlessness after issuing fair warning. He's the violent man who strives to be good. I'm slightly more comfortable with this interpretation. It's explicitly supported by 'The Day of the Doctor's contention that he chose to live up to a set of ideals 'in the name of the Doctor'. That choice implies an internal struggle with the possibility of failure. It's still a much less altruistic version of the character, but perhaps one that makes the pacifist choices more of a noble struggle, the darker moments an occasional relapse. Morally however the character who issues an ultimatum before killing you is not a "Good Man". Whether it's dropping the Sycorax leader or pushing a half-faced droid it's still murder. The choice is even bleaker in this episode since it's not 'surrender or die' but 'kill yourself or die at my hands'. We're not quite in Jack Bauer territory, but I question whether this kind of moral edginess is necessary. Can't we have a more grown-up, more uncompromising and unknowable Doctor who nonetheless refuses to accept the inevitability of violence?
It remains to be seen where the character is headed. In many ways what we see from Capaldi's take on the character is just a continuation of a trend not any great moral earthquake. We don't actually know if he goes through with it, or even if he's bluffing. Capaldi plays it beautifully. I just feel that it's somewhat regrettable as a direction.
I said at the outset that the episode is perhaps a little self-conscious in its remodelling of the Doctor. We're bombarded with statements of writerly intent. There's seemingly endless discussion of his wrinkles and grey hair, not caring if you like him, not being your boyfriend, not flirting, not knowing who the Doctor is any more. It's strange because these things are perfectly evident in the way the character is written and performed without spelling them out every five minutes. It's hard to tell whether Moffat is thumbing his nose at the fans of the Doctor as a romantic lead, or passive-aggressively courting them. Matt Smith's cameo would seem to suggest the latter, and for all its inherent loveliness it feels like a crisis of confidence in the script. Capaldi's Doctor has more than established himself by this point in the episode, but the cameo abruptly backtracks and goes out of its way to reassure us (okay Clara, but she represents the hypothetical audience throughout). I like the timey-wimey-ness, but it's jarring to see the old Doctor just then. It's unnecessary. And worse, when Capaldi asks Clara to "see" him I'm suddenly seeing the actor not the Doctor. A mis-step.
As for Clara, despite taking on the audience-identification role to a degree we probably haven't seen since 'Rose', she's transformed in this episode from her origins as a puzzle-box into a fully realised human being. To be fair, her rehabilitation from plot device to character began in 'The Time of the Doctor', but I loved her in 'Deep Breath'. Bewildered, angry, acerbic and passionate, Jenna Coleman gets to display real range here. It feels like she's been saddled with being one-note 'perky' for so long. She also benefits from the shift to longer scenes that allow proper exchanges of dialogue and not just pithy snippets of wit and exposition. The scene in which Vastra puts her on the spot is excellent, as is her face-off with, er, the face-off droid who wants to burn her face off. Although I understand the criticisms I've seen about all the dialogue that dwells on her appearance and forces her to justify her crush on the Doctor, I really feel that she's a well-written character here. She feels like a person who exists in her own right. It took long enough. Even though her main struggle is still to re-evaluate her relationship with the Doctor, in questioning whether to stay with him she seizes control of something important in her life. She sparkles when trading snark with the new Doctor, and the two arguably have a great deal more chemistry than she ever shared with Matt Smith. Certainly it's more of an even partnership.
Although there's much more to be said about the episode, its really the canvas on which the new Doctor and, yes, the new Clara are painted, so I'm going to leave it there.
EDITED TO ADD: In reading through this I think in getting absorbed in dissection I may have forgotten to simply state that I really enjoyed the episode. I did. It has its faults, and I didn't click with the epilogue, but as an introduction to a new Doctor, and in many ways a new era, it worked far more than it didn't.