Deep Breath (TV story)

 was the first episode of the eighth series of Doctor Who produced by BBC Wales. After a surprise cameo in The Day of the Doctor and a short appearance at the end of The Time of the Doctor, this episode marked the full first appearance of Peter Capaldi as the Twelfth Doctor. Matt Smith as the Eleventh Doctor made an appearance at the end of this episode in a surprise cameo set directly before his regeneration. The episode also introduced Missy, a character whose motives and true identity would remain a mystery until Dark Water, and Courtney Woods, a mischief-making Coal Hill student.

Following the success of the theatrical simulcast of The Day of the Doctor, this premiere episode also received a release in cinemas across the world. It had an extended runtime of seventy six minutes.

Synopsis
Shortly after his regeneration, the Twelfth Doctor arrives in Victorian London, and Clara Oswald struggles to embrace the new man the Doctor has become. All the while, they reunite with the Paternoster Gang to investigate a series of combustions that have been occurring all around the city.

Plot
In late Victorian London, a tyrannosaurus is rampaging in the River Thames, much to the shock of onlookers. When the Paternoster Gang arrive, the inspector is sure Madame Vastra hasn't seen anything like this; however, she comments "not since I was a little girl." Jenny comments the dinosaur is awfully big, with Vastra correcting her on the common size for dinosaurs and its gender; the Tyrannosaurus is a female. The inspector wonders how the dinosaur ended up in the Thames, with Vastra explaining it time traveled.

Seeing the dinosaur coughing, Jenny uses a wrist-worn device to examine it; there is something lodged in its throat. It coughs up the TARDIS, which lands upright on the banks of the river. When the inspector says the dinosaur laid an egg, Vastra rather incredulously, responds by stating, "It dropped a blue box marked police from its mouth...your grasp of biology troubles me". She then gives him a bagful of sonic lanterns, explaining to put them in 20 foot intervals; the devices will emit a signal that will convince the tyrannosaurus to remain in place in the Thames.

The group descends to the bank, where Strax knocks on the TARDIS door, demanding the occupants come out and surrender. The freshly regenerated Doctor opens the door, shushing Strax. He explains a dinosaur was chasing him, but he thinks he escaped. The Doctor and a dishevelled frizzy haired Clara leave the TARDIS, and the Doctor refamiliarises himself with the Gang — albeit poorly, due to his post-regenerative confusion. He shouts for the dinosaur to shut up, before listening to it; the sonic lanterns are giving her a headache, so the Doctor orders the lanterns' frequency to be reduced. Strax questions how the Doctor knew, to which the Doctor calls him Clara and announces his ability to talk to dinosaurs. Clara points out the Doctor's mistake as the Doctor says everything is going dark and wobbly from his point of view. The Doctor decides to pay no mind to his condition, telling everyone to "take five". He collapses, unconscious, with Jenny asking who he is and where the Doctor is. Clara identifies the new Doctor as the same man. Vastra comments, "Here we go again..."

Back at Vastra's house, the Doctor is conscious again and dressed in a Victorian nightshirt, but hyperactive; he demands to know "who invented this room", since he's never used a bedroom before, and having an entire room to be unconscious in seems pointless as you're missing the room. After claiming that a nearby mirror is "absolutely furious", he becomes annoyed about the accent Jenny and Clara speak with, as his accent is now Scottish. Vastra, however, talks "properly" by adopting a Scottish accent which pleases the Doctor; she tricks him into pyschic linking with her, bouncing back an image of perfect sleep into his mind.

Putting the Doctor back to bed, Clara wonders how to change him back; Vastra leaves the room, asking Jenny to fetch her veil. Clara explains to Jenny how confused she is about the Doctor's new incarnation: he's old and grey, even through it's a new body. When questioned how she'd react if Vastra was different, Jenny points out that Vastra isn't even human and that she loves her anyway before leaving. Watching over the Doctor, Clara hears the dinosaur wailing. The Doctor mumbles in his sleep, seemingly translating its roars into a lament for its lost world, ending with, "Can't see me. Doesn't see me," which Clara believes refers to the dinosaur. Strax comes in and escorts Clara to Madame Vastra, who asked to have a word with her.

Outside on the street, people are still looking at the giant dinosaur. A man called Alf guesses the tyrannosaurus is part of a government plan, in conversation with his wife. Alf then says to a mysterious man there is something wrong with the dinosaur's neck, that makes it look unreal. The man replies that Alf has good eyes, and he needs them as a gift to replace his bad eyes. He reveals the other side of his face — it looks like a clockwork robot — and then proceeds to remove Alf's eyes.

In Vastra's study, she questions Clara about how she and the Doctor came to be in Victorian London after Trenzalore. When Clara says that the Doctor is gone, Vastra corrects her by stating he renewed himself; this amuses Clara, who finds it ironic as the Doctor's new form is aged. Vastra goes on to state that the Doctor wears a face as she wears a veil, and that is to be accepted; she wears a veil to hide her face as a judgement on the hearts of others. The conversation escalates as Clara thinks Vastra is judging her, but Vastra retorts by implying that Clara is judging the Doctor because he is no longer the handsome young man she met. Clara explodes, insisting that she is not so shallow that the previous Doctor's looks are what made her travel with him. Jenny applauds, surprising Vastra; Vastra laughs that she wondered what Clara would be like when angered. Vastra explains that the Doctor needs all of them — especially Clara — as anchors to find himself again. When Clara realises that Vastra has removed her veil, she wonders when that happened; "When you stopped noticing it".

Upstairs, the Doctor wakes up smelling something. After sniffing about on the floor, he finds a piece of chalk. He writes Gallifreyan calculations with the chalk around the whole room, including on the walls and floor. Hearing the dinosaur roar, the Doctor heads to the door; however, he finds it "boring; not me". He then proceeds to climb out of the window ("Me!!") and on to the roof; he shouts across London at the dinosaur, apologising for getting his time machine stuck in its throat. However, just as he vows to get it home safely, the dinosaur spontaneously bursts into flames and collapses, to his horror.

Inside the house, Vastra and the others hear the dinosaur wail in agony, and call for Strax to prepare the carriage. Outside, the Doctor jumps off the roof and lands in a tree. Falling from the tree and getting stuck on a branch, he stops a horse and carriage and asks that he will need to relieve him of his "pet", much to the driver's confusion. The Doctor replies that he was talking to the horse. Jumping onto the horse, he uses the sonic screwdriver to cut the ropes linking the horse to the carriage. As the Doctor struggles to properly control the horse (and also fails to tell his "new hands" apart), the Paternoster Gang and Clara unknowingly follow him.

The Doctor arrives at the bridge and quietly observes as the dinosaur burns in the flames. The Paternoster Gang arrives, with Clara questions the Doctor's sudden appearance here; Vastra explains the Doctor goes wherever there is trouble. They wondering who would do such a thing. The Doctor says that's not the real question, nor is "how". The question is: "Have there been any similar murders?" Vastra admits there have been similar ones. The Doctor then asks if humans are watching the dinosaur's corpse burn, then who would be calmly walking by: he points to the mechanical man who stole Alf's eyes, who is ignoring these strange events completely. The Doctor jumps into the Thames. Clara worries that he'll drown, but Vastra explains that the Doctor has taken up the case — the only way to find him again is to do the same.

Clara washes up the next morning, taking notice of Strax's voice out the window; he is threatening workmen to be careful with unloading the TARDIS. Greeting Clara, Strax explains the Doctor will always come looking for his time machine, and "By bringing it here, he will be lured from the dangers of London to this place of safety, and we will melt him with acid." Clara retorts "OK, that last part?" Strax apologises for his verbal fumble, citing it's an old habit. Clara asks for "The Times" to be sent up to her. Strax promptly throws the paper up to Clara, striking her in the face and knocking her down.

Now in a Victorian dress, Clara makes her way downstairs and meets Jenny, who warns her not to disturb Vastra as she is investigating other cases — including having a child poisoner for dinner (literally), so she had best stay out of the larder (it will get noisy later). Knowing that Clara is still worried about the Doctor, Jenny explains that they have the Paternoster Irregulars out in force to track him down.

Clara encounters Strax once again, who offers her water. Clara at first accepts, but then declines when Strax gives her the bucket of water he has been using to mop the floor (and had previously bathed in). Strax then gives Clara a medical examination, finding her spleen to be in enviable great condition. He moves on to her head, stating she's 27 years old (and is silenced about her life expectancy, though not before indicating her prognosis for a long life is excellent) and tries figuring out the image he's seeing in her subconscious. Strax explains Clara may end up serving with him, as London has many dangerous thugs who could kill the Doctor in his current state.

In a dirty alley somewhere, the Doctor examines his new face in a small mirror and rummages through debris. As a disheveled old man stumbles by, the Doctor is confused over why he now has this face. Ranting and belligerent, he asks the man's input on why he gave himself this face, noting it's familiar to him. The Doctor asks the confused and frightened man if he has seen his face before; the old man indicates he hasn't. Intimidated by it, he says he doesn't like the Doctor's face—the Doctor's not too fond of it either, due to a new, potent set of "attack eyebrows" that seem like they want to cede from the rest of his face and "set up their own independent state of eyebrows". Playing along with the Doctor's madness, the old man agrees he has mighty eyebrows. The Doctor then notes that he has a Scottish accent, which the man confirms; he rants on that he can now complain about things, before demanding the man's coat. The man whimpers in fear, until the Doctor brings up a newspaper, showing the article "Fourth Case of Spontaneous Combustion". The man wonders what "devilment" it is; the Doctor doesn't know, but says he'd probably blame the English.

In Vastra's study, she is busy in front of a board, with Jenny posing for her in her underthings. Vastra goes on to explain about spontaneous combustion, confirming Jenny's question if it's similar to "love at first sight". Vastra turns the board, revealing a map and the locations of the incidents; Jenny is not too amused that her wife had her posing for no good reason. Clara barges in, which Vastra mistakes as Clara wanting to take Jenny's place posing. However, Clara shows her the adverts; there's a notice in the paper addressed to the "Impossible Girl" — the Doctor's nickname for her. Unfortunately, it doesn't say where to meet, except for "on the other side"; guesses are: the other side of London, or the other side of regeneration after he's recovered. However, Clara knows the Doctor isn't complicated, and "frankly doesn't have the attention span" for puzzles (especially now). Deciding to keep the meaning of the phrase simple, Clara checks the other side of the same page, finding Mancini's Family Restaurant is the meeting place the Doctor has chosen.

Clara arrives at the restaurant and is soon joined by the Doctor, now wearing the tramp's coat; he traded his favorite watch for it. The Doctor tries to laugh to lighten the mood, but Clara is angry with him; she asks what kind of person would put a cryptic message in the paper instead of sending a note to someone they've known a long time. The Doctor says it would be an egomaniac needy-game player, to which Clara says is something that hasn't changed; however, the Doctor says he doesn't want her to change and doesn't mind playing her games, having figured out the puzzle. They argue over if the message is "for" or "from" the Impossible Girl, before realising neither of them placed the ad; however, Clara then realises the Doctor insulted her.

While Clara is upset, the Doctor is more interested in their surroundings. He makes Clara look at the diners and notice how they are mechanically cutting food and bringing silverware to their mouths — but not actually eating anything. The Doctor then uses a hair from his head, then Clara's, to test the atmosphere, and realises the diners aren't breathing either. The two stand up to leave, only for every diner in unison to rise and block them off, forcing them to sit again. A waiter comes over to scan the Doctor with an advanced gadget and recite various body parts. Clara wonders why such things would be on the menu, but the Doctor informs her they are the menu. He reaches up to remove the waiter's face, revealing a mechanical form underneath. He presses the face to Clara's own to show her — to her horror — it's an actual human face. The waiter locks them into their chairs as the booth lowers itself into a tunnel.

Finding themselves in a chamber below the restaurant, the Doctor says it functions as a larder; it's cheaper to keep them alive until they're needed for parts. The Doctor plans to drop the sonic screwdriver onto the floor and have Clara pick it up with her feet, then toss it to him. As Clara tries reaching the sonic, the Doctor mutters he misses Amy. Clara grabs the sonic, tossing a bit too low; however, it does land in the Doctor's lap. Sore in more than one sense, the Doctor frees them, with Clara asking why the sonic screwdriver wasn't voice-activated before realising he had forgotten it was.

They make their way to a chamber and find the Half-Faced Man from before sitting in a chair. Around him are pods containing other droids, all dressed and resembling real Londoners. Examining the Half-Faced Man, the Doctor realises it's recharging and this is not a typical cyborg — but a robot who adds human flesh to himself. The restaurant is their way of capturing random humans to harvest their flesh and organs for themselves, since they require a constant supply of spares to replace their rotting organic parts. The cases of "spontaneous combustion" are their way of killing the victims quickly to hide the evidence of mutilation, including the dinosaur.

The Droid begins to awaken and the Doctor and Clara start to run. A door slides closed between them, Clara begging the Doctor to let her in but the Doctor shocks her by saying it's better they're not both captured and leaves her behind. Clara remembers the Doctor saying that the robots don't breathe and holds her breath as she tries to walk to the exit. She nearly makes it but eventually is forced to take a breath and passes out, remembering taunts from her unruly pupils in the past. She had made the mistake of using the biggest threat she could make (expelling them) first, leaving nothing else to scare the children with. The students proceeded to laugh at her.

Waking up, Clara is confronted by the Half-Faced Man, who demands to know where the Doctor is. Knowing it's logical, Clara states she will not talk and killing her will have the same result — loss of information. Clara offers it a deal: a question for a question. She asks why it killed the dinosaur and is told it was to harvest its optic nerve. Clara realises the Half-Faced Man was specific, knowing exactly what a dinosaur's organs were like, and asks how old it is. The Half-Faced Man states they have been working for millions of years to rebuild themselves over and over, all in search of the "Promised Land." It threatens to kill Clara but she remains strong and defiant despite her obvious fear; it then decides torture would be an effective way of getting information from her.

When it asks once more where the Doctor is, Clara replies that if the Doctor is still the Doctor, he will be right behind her and extends her hand behind her. She whispers for him to be there and suddenly, one of the robots grabs her hand. He pulls her back before peeling off his mask to reveal himself as the Doctor in a new suit who thanks the "Rubbish robots from the dawn of time" for "all the gratuitous information." He places his sonic screwdriver into the charger, warning the Half-Faced Man he will blow the entire room if he sees one thing he doesn't like "and that includes karaoke and mimes, so take no chances." Clara is still upset over being left behind as the Doctor states he's not really sorry about that. The Half-Faced Man asks why they are there and the Doctor replies because of the ad in the paper. The cyborg's confusion makes the Doctor and Clara realise he didn't place the ad, with the Doctor hugely embarrassed at his blunder and asking that nobody ever mention that again.

The Doctor tells Clara to "say the word" and with reluctance, she touches her brooch, which lights up as they both intone "Geronimo." From a hole in the ceiling, Vastra and Jenny (in leather catsuits) twirl down attached to curtains; Strax falls after them. Vastra reports the restaurant has been "disabled with maximum prejudice" and the police summoned (with Clara asking the Doctor why they never call the police — they should start doing that!). The Half-Faced Man calls in more robots as the Doctor states killing isn't their way. Clara protests the restaurant is a slaughterhouse and the Doctor shrugs it's no different than any other restaurant. The Half-Faced Man declares again that they are in search of the Promised Land, but the Doctor snaps that after millions of years, he should know it doesn't exist. The Half-Faced Man makes his way to the booth elevator and rises up with the Doctor hanging on to its bottom while Vastra, Jenny and Strax are left to fight the other robots.

The police are in the restaurant, stunned at its mess when the Half-Faced Man arrives and informs them it is closed, showing off his flame-thrower arm as a hint. The police leave, the head detective declaring the restaurant off-limits to anyone before ordering one of the constables to get reinforcements. Back inside, the Doctor is sitting at a table, pouring a drink into a glass, telling the Half-Faced Man he is afraid he is going to have to kill him and offers it a drink first. The Half-Faced Man moves to a control panel with the Doctor following and observing the controls. The Doctor states there is no way to escape, but the Half-Faced Man stating that the escape pod is there. The Doctor insists the pod cannot have enough power but the restaurant shakes. As the police outside stare in shock, the restaurant rises up, lifted by a hot air balloon made of human skin. Below, the rest of the group continues to fight the robots, who keep rising up after stabs and laser blasts.

The Doctor examines a control button that fell off; this pod belonged to the SS Marie Antoinette, sister ship to the SS Madame de Pompadour, but despite how familiar it all is, he cannot place it. The Doctor realises the ship fell through time, crashing in England millions of years earlier. The only survivors were the service robots, who began their cycle of repairing themselves over and over again. He tells the Half-Faced Man to look out the window at London. The Half-Faced man says it is beautiful. The Doctor disagrees, saying it looks tiny and far away from up here. He prefers it down there. The humans are never small to him, and he will fight for them.



The Half-Faced Man continues to talk on the need to find "the Promised Land" as the Doctor rails on him for the fact that he's rebuilt himself so many times that all trace of his original self has been lost, comparing him to a broom that is broken and rebuilt but still not the same broom. He holds up a silver plate to say the Droid does not even know where he got that face from. As the Half-Faced Man stares at his reflection, the Doctor does the same. He finishes by saying that he knows that killing this cyborg will stop all the others and will do so for Earth. They struggle at the window as below the Gang are overwhelmed by the robots. Clara suggests they hold their breaths, the robots freezing as they do. It's too much for Jenny, but Vastra gives her a long kiss to share oxygen. Just as Strax is about to take his own life, all the robots collapse. Above, the Half-Faced Man is shown impaled on the spire of Big Ben as the Doctor looks out, his expression grim.

The Gang return to Vastra's home to find that the Doctor and the TARDIS have both vanished. Later, Clara (back in her modern clothing) asks Vastra if she's got a vacancy since it looks like she's stuck in Victorian times, but Vastra assures her he'll be back; she even further points out that Clara has changed in preparation for returning home. She's proven true as the TARDIS returns, telling Clara "Give him hell; he'll always need it" as she happily runs off.



Clara finds the interior changed, with a lighter shade of mood lighting in the time rotor and some furniture about, with the Doctor seated in a chair. The Doctor admits he's not sure about the new look himself after Clara says she doesn't like it, muttering that he used to have more round things, wondering where they went. The Doctor tells Clara "I've lived for over two thousand years, and not all of then were good. I've made many mistakes, and it's about time I did something about it." He tells her that he is not her boyfriend, which she interprets as her being at fault, until the Doctor addresses that it wasn't her mistake.

The Doctor puts the TARDIS in flight, takes a step back, and partially unbuttons his new suit jacket, exposing a flashy red lining inside to show off his new look to Clara. She grins in approval, and then the Doctor gets right to business, wondering how she got the TARDIS telephone number. Clara asks who put the ad in the paper and the Doctor reminds her of the woman in the shop long ago who gave her the number of a computer help line that instead connected her to the TARDIS. It seems someone wants the two together, and maybe they should find out who.



The TARDIS lands, and the Doctor wonders how Clara feels about staying on as that mystery woman seems to want. Clara, still having mixed feelings at this new incarnation of the Doctor, is unsure if she wants to stay his companion, saying that she doesn't think she knows him anymore. Her phone begins to ring. The Doctor teasingly suggests she should get that call, because it might be her boyfriend. Staring away from the Doctor, she tells him to shut up because she doesn't have a boyfriend.

Clara walks out of the TARDIS in modern times to answer the call, and is shocked to hear the voice of the Eleventh Doctor. He explains he's calling through time from Trenzalore just minutes before he changes. Clara, remembering how she found the TARDIS telephone dangling off the hook from the call box, begins to tear up from hearing from him again. He says that the man before her is still him — just changed. Holding back her tears, Clara asks him why he would do this. The Eleventh Doctor explains that he's phoning her because he thinks this regeneration "is gonna be a whopper", and that she may be afraid. The new Doctor will be, he says, even more so and needs her help to handle all this. She should not be afraid, for his sake. The Twelfth Doctor, now outside the TARDIS also, asks her who is on the phone. The Eleventh hears as asks her if that's the Doctor. The Twelfth Doctor then asks her the same question — "Is that the Doctor?" When he hears the voice of his future self, the previous Doctor groans over "turning old", which makes Clara laugh, as she also confirms his hair will be gray as well. He's not at all impressed at the discovery that he'll have gray hair, noting how young he was in his soon-to-change appearance. The Eleventh Doctor says a final goodbye to Clara before he hangs up.

The new Doctor asks Clara if she will do as she was asked on the call, and help him. She says he shouldn't have been listening, but he replies that he wasn't — that was him on the call. he then bemoans that Clara still can't see him. Upset that she's looking right through him but doesn't view him as the same person, the Doctor begs, "Just see me." Clara walks up to the Doctor and gives him a good look over, and concentrates on his eyes. She beams, thanking him for phoning from the past.



Clara hugs him, to which the Doctor looks a bit confused and wonders where he should put his hands. He says that in his current incarnation, he doesn't think hugging is his thing. She's unsure he's entitled to a vote. Clara offhandedly says they're not at her home, and the Doctor apologises. He reveals they're in Glasgow, Clara pointing out he'll fit in with the accent. Tey go off in search of chips and coffee... with the Doctor revealing Clara will have to pay for them as he has no money. However, she thinks he's the fetching sort. Although the Doctor is willing to debate this, Clara still isn't sure he should get a vote. They stroll off together in search of coffee, the Doctor still hesitant.



Elsewhere, the Half-Faced awakens in a beautiful garden, and replaces his top hat on his head. A mysterious woman calls out to him, introducing herself as ; she inquires if the cyborg killed himself or if the Doctor pushed him, since she couldn't tell. Missy goes on claim that the Doctor is her boyfriend, and that she likes his new accent. Over his initial discombobulation, the Half-Faced Man then asks where he is. Missy laughs, asking him where he thinks he is; she goes on to explain he finally reached the "Promised Land" at long last, and that it is a paradise. The woman grandly introduces his new home, "Welcome... to Heaven". She chomps her teeth fatuously, then begins prancing and twirling around an ornate fountain with an umbrella in hand...

Cast

 * The Doctor - Peter Capaldi
 * Clara - Jenna Coleman
 * Madame Vastra - Neve McIntosh
 * Strax - Dan Starkey
 * Jenny - Catrin Stewart
 * Half-Face Man - Peter Ferdinando
 * Inspector Gregson - Paul Hickey
 * Alf - Tony Way
 * Elsie - Maggie Service
 * Cabbie - Mark Kempner
 * Barney - Brian Miller
 * Waiter - Graham Duff
 * Courtney Woods - Ellis George
 * Policeman - Peter Hannah
 * Footman - Paul Kasey
 * - Michelle Gomez
 * and Matt Smith as The Doctor

Uncredited

 * Clockwork Droid - Clem So

The Doctor

 * The Doctor enhances the TARDIS control room with furnishings such as a chalkboard, bookshelves, and a recliner. He also changes the cold blue neon piping in the time rotor to a warmer amber.
 * The Doctor declares he doesn't like karaoke or mimes.

Species

 * Silurians have a greater lung capacity than humans.

Culture

 * The Doctor describes his and Clara's situation in the restaurant as "Sweeney Todd without the pies".
 * Clara likens the body-part harvesting to an alien version of Burke and Hare.

Story notes

 * There are several references and allusions to Arthur Conan Doyle's Sherlock Holmes stories, which were previously revealed as being based on Madame Vastra's exploits (TV: The Snowmen):
 * In this episode, Inspector Gregson helps the Paternoster Gang.
 * The Paternoster Gang uses "Paternoster Irregulars" to find the Doctor.
 * After discovering the advertisement, Madame Vastra exclaims, "The game is afoot!", a line originally from William Shakespeare's play Henry V, but more commonly associated with the Holmes stories.
 * At one point, Jenny mentions "the Conk-Singleton forgery case" and "the Camberwell poisoning case". Both cases are referred to in the Canon.
 * At another point, Vastra is shown reading the agony column, a frequent habit of Sherlock Holmes'.

Common among all versions

 * The story's premier broadcast date, 23 August, is the same date as the in-universe setting of The Fires of Pompeii, in which Peter Capaldi made his first appearance in Doctor Who as Lobus Caecilius.
 * Additionally, during a scene where the Doctor sees his new face he remarks that he'd seen it before. At the time this was thought to have been a joke about Peter Capaldi having played Caecilius the Series 9 episode The Girl Who Died would actually make this moment a plot point, revealing the Doctor had regenerated to look like Caecilius to remind himself he can always save people no matter how wrong or impossible it seemed, just as the Doctor had saved Caecilius during his tenth incarnation.
 * Matt Smith's cameo was recorded during the filming of The Time of the Doctor, as confirmed by Steven Moffat in several interviews following the preview screenings.
 * Moffat joked that Matt's return was the fastest return ever, considering the fact that he last appeared in the previous episode. Indeed, disregarding recaps, the Second Doctor momentarily seeing an image of the First Doctor in TV: The Power of the Daleks, and the special case of the 1996 TV movie, this marks the first time a former Doctor has made a substantial appearance in the very first episode of his successor's era.
 * This episode (and its script) was leaked online when stored on a publically-accessible server, with incomplete CGI, watermarks and time codes in black-and-white, prompting a plea from BBC Worldwide not to watch it. The rough cut held the nomenclature, "Prepared for Marcelo Camargo at Drei Marc".
 * The BBC gave this episode a world tour in seven countries over twelve days.
 * No shots of the TARDIS interior are shown before the reveal of its redesign, due to the permanent remodeling of certain parts in the control room for Peter Capaldi's Doctor, which would make the replication of the pre-redecorated console highly tasking.
 * During the read-through of the script for this episode (seen in DOC: Doctor Who Extra), the cast and crew members filled the room with laughter when Peter Capaldi reached the lines ridiculing his eyebrows.
 * The read-through was also the first time that Capaldi and Jenna Coleman had worked together, as Capaldi had been secretly auditioned.
 * Near the day of filming where Capaldi's official costume would be seen in public for the first time, the BBC released an official publicity shot to deter a press leak.
 * When the Doctor wears a human head as a disguise in the Clockwork Droids' lair, the face on the head is actually that of his previous incarnation. This was due to the planned mask becoming unavailable for filming, forcing the production team to hastily grab a spare without paying much attention to it; it wasn't until filming finished that the crew realized that they grabbed a Matt Smith mask. The unintentional symbolism of the Doctor ripping off his previous face later in the scene was noted by the staff in a behind-the-scenes video for BBC America's "The Doctor's Finest".
 * Digital raindrop removal was used in the scene where Clara and the Doctor emerged in Glasgow (actually Cardiff), since it was a brisk, overcast day that saw a small downpour during filming. Jenna and Peter used insulated coats to stay warm when they were not in the middle of filming.
 * The role of Barney the tramp was played by Brian Miller, the husband of the late Elisabeth Sladen, who had previously appeared in TV: Snakedance and TV: The Mad Woman in the Attic.
 * This is the first TV story to be sandwiched between two Dalek stories since The Myth Makers in 1965, which aired between Mission to the Unknown and The Daleks' Master Plan. While those two stories were intertwined, however, The Time of the Doctor and Into the Dalek, which aired either side of Deep Breath, are separate stories.
 * Rachel Talalay directed Missy's scene because Ben Wheatley was unavailable.

The Hanshaw Title Sequence

 * This episode saw the debut of a new title sequence designed by Billy Hanshaw after executive producer Steven Moffat saw a video of his conceptual Doctor Who titles sequence on YouTube and decided to draft him aboard to do a professional version of his sequence. The new titles features a vast expanse of golden-bronze clock gears whizzing by in empty space, and then the TARDIS flying through a tunnel of Roman numeral clock face numbers spiraling into a literal depiction of a time vortex with glowing engravings of circular Gallifreyan. The TARDIS passes across the screen in a way very similar to the Series 1 title sequence as the TARDIS jumped from the blue to red time vortex, and then launches past a group of planets. Peter Capaldi's piercing eyes are shown, rather than a full insert of the actor's face.
 * Moffat explained in an interview, "I happened across it [the title sequence], and it was the only new title idea I'd seen since 1963. We got in touch with him, and said, 'OK, we're going to do that one.'" Billy Hanshaw responded, "I had to pinch myself because I didn't know if it was really happening. It's one of those stories about people putting something on YouTube — it's usually a musician this happens to. They put a performance on there and they get picked up by a label. It's a similar kind of story. I thought, these things don't generally happen."

Specific to theatrical presentation

 * A five-minute "prequel" was shown before this episode, consisting of a specially recorded scene similar to the Strax Field Reports, featuring the Paternoster Gang: Vastra, Jenny Flint, and Strax. The scene primarily focused on Strax humourously describing the first twelve incarnations of the Doctor, making note of the War Doctor as well as the Tenth Doctor's aborted regeneration, to his people, before alerting them to the appearance of the latest Doctor. He also made fun of the Ninth Doctor's ears and the Eleventh Doctor's chin, expressed his disgust with the Eighth and Tenth Doctors' romantic habits, and described the First and Tenth Doctors as women.
 * The first installment of Doctor Who Extra, a new documentary series conceived as a smaller scale replacement for the former Doctor Who Confidential, which was cancelled by BBC Three, ending with Series 6. Otherwise exclusive to BBC iPlayer, this initial installment was screened to participating cinemas following the showing of Deep Breath and focused on both the production of this episode and Peter Capaldi's inauguration as the Twelfth Doctor. It was subsequently also made available on YouTube.
 * Doctor Who Extra was in turn followed by a live Q & A in London, hosted by Zoe Ball with Peter Capaldi, Jenna Coleman, and Steven Moffat. Reportedly due to transmission problems a number of cinemas were unable to screen this. This feature was only shown at screenings that occurred in the UK on 23rd August 2014. Later theatrical screenings of the episode in Canada, the US and elsewhere only featured the prequel and Extra.

Ratings
9.17 million (DWM 478)

Filming locations
The Maltings, Pontprennau

Mount Stuart Square, Cardiff

Queen Street, Cardiff

Production errors

 * The end of Vastra's mask is visible during the opening scenes.
 * When the Doctor is in bed, Jenny walks to the window and looks up to see the dinosaur. But in the next shot, the T-Rex is clearly at eye-level.
 * When the Half-Face Man wakes up in "Heaven", he clearly has a left brow, despite him only having a right half of a face.
 * The dinosaur slime that covers the TARDIS appears to disappear from the door when the scene shifts to show Strax knocking.

Continuity

 * The Cloister Bell is heard as the Doctor collapses on the bank of the River Thames. (TV: Logopolis, Doctor Who, et al.)
 * The Doctor often reflects that he finds the current situation of robots harvesting human organs to repair a ship to be naggingly familiar, but his regeneration-addled brain is unable to remember. (TV: The Girl in the Fireplace)
 * The Doctor mentions Amy, making reference to her long legs in comparison to the much shorter Clara. (TV: The Impossible Astronaut)
 * While performing a physical examination of Clara, Strax makes an observation on her thorax, as did Linx with Sarah Jane Smith (TV: The Time Warrior) and Commander Skorr with Martha Jones. (TV: The Sontaran Stratagem)
 * The Doctor wonders who gave Clara the phone number of the TARDIS. (TV: The Bells of Saint John) This isn't solved until the season's final episode, Death in Heaven.
 * The Doctor is sure he has already seen his new face before, and comments that it has frown lines that he didn't frown. (TV: The Fires of Pompeii)
 * Clara learns why the TARDIS telephone was hanging off the hook when she returned to the TARDIS after the Eleventh Doctor began regenerating. Because he did not patch it back to the console unit, the Eleventh Doctor dragged the phone by its cord into the entrance of his console to make a private, final phone call to Clara in the near future. (TV: The Time of the Doctor)
 * During his phone call to Clara, the Eleventh Doctor says that his regeneration is "gonna be a whopper." When describing his imminent regeneration to the Daleks on Trenzalore, he said exactly the same thing. (TV: The Time of the Doctor)
 * The Twelfth Doctor's claim to speak "Dinosaur" echoes the Eleventh Doctor's claims to speak the languages of horses and babies. However, this claim is not played for laughs, and seems less dubious - especially when considering the Doctor's translation of the stranded dinosaur's lament. (TV: A Town Called Mercy, A Good Man Goes to War, Closing Time)
 * The Doctor and Clara say "Geronimo!" as a code word to spring the Paternoster Gang into action, a catchphrase used by the Doctor's previous incarnation. (TV: The End of Time et al.)
 * Jenny snaps at Vastra for calling humans monkeys, or apes, as Silurians often have. (TV: Doctor Who and the Silurians, A Good Man Goes to War)
 * Strax again mentions using deadly acid as a weapon. (TV: The Crimson Horror)
 * When Clara sees the improved console room, she says, "You've redecorated... I don't like it." This was said by both the Second and Tenth Doctors at the sight of new TARDIS console designs. (TV: The Three Doctors, The Day of the Doctor) The Second and Eleventh Doctors have also said this about other rooms. (TV: The Five Doctors, Closing Time)
 * The Doctor wishes he had more "round things" in his updated control room. (TV: The Day of the Doctor) He remembers he "had many round things once" and wonders where he put them. (TV: An Unearthly Child onward)
 * Clara's last interaction with the Eleventh Doctor takes place on the phone, mirroring the first interaction she had with him as an adult. (TV: The Bells of Saint John)
 * The Doctor states that he is now over 2,000 years old. (TV: The Time of the Doctor, PROSE: Tales of Trenzalore: The Eleventh Doctor's Last Stand)
 * The Doctor once again confirms that he does not see the human race as "small" (TV: The End of Time, Hide)
 * The Doctor remembers that he wore a scarf once. He dismisses the idea to have one as it will look stupid (TV: Robot et al.)
 * After the Doctor collapses, Jenny asks Clara who he is and Clara replies that he is the Doctor, mirroring a conversation Rose and Jackie Tyler had after the Ninth Doctor's regeneration. (TV: The Christmas Invasion)
 * After seeing the new Doctor, Madame Vastra says "Well then, here we go again.", just as the Brigadier did after the Third Doctor's regeneration. (TV: Planet of the Spiders)
 * This line by Madame Vastra suggests that she may have helped a previous Doctor recover from a regeneration. The War and Ninth Doctors are the only candidates, the aftermath of the other Doctors' regenerations having been witnessed. (TV: The Power of the Daleks, et al.) However, the War Doctor seems to suffer no ill effects from his regeneration and is in the company of the Sisterhood of Karn, making the Ninth the most likely candidate.
 * Clara recalls her first day working as a teacher in Coal Hill School. (TV: The Day of the Doctor)
 * Strax continues to call Clara "boy", as he still has trouble telling male and female genders apart. (TV: The Snowmen, The Crimson Horror)
 * This is the second time that Clara asks the Doctor who Amy is, as she previously did when he referenced her as "Amelia". (TV: The Time of the Doctor) This is despite her having once viewed a photograph of Amy. (HOMEVID: Clara and the TARDIS)
 * The Doctor wonders where he got his face. Romana deliberately chose her new appearance based on someone she had previously met. (TV: Destiny of the Daleks)
 * Clara reveals she had a poster of the philosopher Marcus Aurelius in her room when she was 15. She previously quoted him in her classroom. (TV: The Day of the Doctor)
 * A dinosaur whom the Doctor befriends is brutally killed, as happened when "Tricey" was shot by Solomon's robots. (TV: Dinosaurs on a Spaceship)
 * The Doctor previously took a companion to Scotland accidentally when trying to take her home. (TV: School Reunion) Unlike Sarah Jane Smith, Clara will only wait three weeks for the Doctor to return. (TV: Into the Dalek)
 * The reason for the Doctor accidentally bringing a dinosaur with him through time, along with getting the TARDIS stuck in its throat, could very well be because as soon as he regenerated he completely forgot how to fly the TARDIS. (TV: The Time of the Doctor)
 * The Doctor had previously encountered beings who were continuously "repaired" for so long that he presumed that there were likely nothing of the original person left. (TV: The Doctor's Wife)
 * When Clara agreed to some coffee in Glasgow she told the Doctor to pay and he said he didn't have any money. He previously said the same to Rose Tyler when she wanted some chips and told him to pay. (The End of the World) The Third Doctor also needed to borrow some change from Liz Shaw to call UNIT to ask for a waxworks exhibition to be raided. (TV: Spearhead from Space)
 * The Doctor is now against hugging, something he will later point out several times. (TV: Listen, Death in Heaven)
 * While trying to persuade Clara to stay with his next incarnation, the Eleventh Doctor asks her to "Help him." Unknown to him, it was through those same words that Clara persuaded the Time Lords to grant him a new cycle of regenerations. (TV: The Time of the Doctor)
 * Vastra claims that Clara knows the Doctor better than anyone. This is not an exaggeration, as she is the only known person to have witnessed his entire life. (TV: The Name of the Doctor)
 * The Doctor once again asks who gave Clara his number when he first called her, to which she once again answers . (TV: The Bells of Saint John)
 * In the alley scene, the Doctor suddenly exclaims, "Shut up! I missed something. I saw…what did I see?" This is nearly identical to a line from the Eleventh Doctor's first story, when he notices Rory taking a picture of Prisoner Zero instead of looking up at the sky going dark like everyone else. (TV: The Eleventh Hour)
 * Clara gets upset when the Doctor calls her a control freak and emphatically denies it, even though she admitted to being one while under the influence of the Truth Field on Trenzalore; in Clara's personal timeline, this would in fact have been no more than a couple of days earlier. (TV: The Time of the Doctor)

DVD releases

 * Doctor Who: Deep Breath. The release included the cinema prequel, Doctor Who Extra and Doctor Who Live: The Next Doctor. The Region A release also featured The Real History of Science Fiction.
 * Doctor Who: Series 8 Boxset

Blu-ray releases

 * Doctor Who: Deep Breath Blu-Ray
 * Doctor Who: Series 8 Blu-ray Boxset

Digital releases

 * The episode was released on Google Play, iTunes and Amazon Instant Video in HD or SD, also available as part of the Series 8 digital boxset. The digital boxset contains various features: trailer, interviews, The Ultimate Companion, The Ultimate Time Lord, Inside the World Tour and Doctor Who Extra episodes for each episode.
 * In the US, the series was released through digital streaming services Hulu and Netflix with a subscription.