The terrifying Skovox Blitzer is ready to destroy all humanity - but worse, and any second now, Danny Pink and the Doctor are going to meet.

When terrifying events threaten Coal Hill school, the Doctor decides to go undercover.

This was a wise and thoughtful opening gambit from Moffat, and from the wonderful Capaldi – if you can utterly disregard the demented plot. Granted, this might be like saying "apart from that, 6 August was a typically pleasant day in Hiroshima", but the underlying, and cleverer, theme was of age, and ageing, and looks, and perception, very nicely summed up when Clara (Jenna Colman, in a performance of great nuance if you can forget that last faux-Scots diphthong) asks the pretty lesbian lizard-lady, "When did you suddenly stop wearing that veil?" "When you stopped seeing it," comes the reply.

The whole thing is daft, some say. Certainly the plots, much of the bangy noise, and all of the hype. But some tremendous subtleties emerge. The restaurant scenes were genuinely scary. And Commander Strax, that cross between R2D2 and a pepperoni Wayne Rooney, for instance taught last night's teenagers a great difference by saying "it is to be hoped" (correct) rather than the over-misused "hopefully".

Euan Ferguson, The Observer

In the spirit of empathy, you might have wondered what younger viewers – if children still watch Doctor Who – were supposed to make of such existential hand-wringing while they were waiting for the fighting to start. To be fair, there was a smattering of comedy to enjoy as Clara exchanged amusing cultural misunderstandings with some of the Doctor's old plasticky alien acquaintances, but the jeopardy – clockwork zombie androids harvesting body parts – was a long time coming and lazily derivative in form (knowing acknowledgements to Burke and Hare and Sweeney Todd didn't make it less so). The excitement was over before Capaldi had the chance to stamp his personality on things.

Phil Hogan, The Observer

Peter Capaldi’s 12th Doctor has probably been the most fiercely anticipated new leading man in the show’s history. And in the end he was … probably exactly how you would imagine Peter Capaldi playing the Doctor to be. Not the Malcolm Tucker clone that Tumblr had so much fun anticipating, but far from an easy sell, either. We saw, at the end, the vulnerability underneath, but it took a bloody long time to get there. And when the 11th Doctor turned up at the end to reassure Clara that this was the same man (surprise! And well done if you managed to avoid that spoiler), he was pretty much doing the same for the audience.

Deep Breath was a gothic period drama, true to promises of a show with a grittier tone and longer, more grounded scenes. In many ways, it was surprisingly low-key for a series opener. In reality, it maybe could have done with being shaved down to an hour.

It’s a measure of Doctor Who’s madness that our familiar territory is the Victorian household of a lizard detective, her ninja housemaid wife and their Sontaran butler, but here we are, and it’s lovely and familiar to have them back. Neve McIntosh as Madame Vastra is emerging as a true star of the show, and she gets fleshed out, with her blunt condemnation of Clara’s attitude and her lustful manipulation of Jenny. Here is an inter-species lesbian couple in the 19th century that you can actually believe in.

Dan Martin, The Guardian

Writer Steven Moffat’s smart dialogue got the jump on viewers by second-guessing how they would be commenting from the sofa: there were references to Capaldi being grey, wrinkly and Scottish (like Moffat himself). His first word was “Shush!”, as if silencing potential naysayers. Capaldi signals a conscious break from the Doctor’s boyish recent incarnations. A blend of Doctor Doolittle and Sherlock Holmes, he crackled with fierce intelligence and nervous energy. Whether riding a horse in his pyjamas or dismissing Earth as “planet of the pudding brains”, he was a class act. His unpredictable air added dramatic tension. Twice he abandoned Clara and it was uncertain whether he would come back for her.

Along with its new leading man, the show had taken the opportunity to spruce up in other aspects. There was a new credits sequence (with the usual time tunnel being replaced by rather literal clocks and cogs), a tweaked, squeaky theme tune and a redecorated Tardis (an industrial look which rather complemented Capaldi’s all-black outfit). The tone seemed different, too, quieter and more thoughtful – less about running down corridors holding hands, more about self-discovery and redemption.

Michael Hogan, Telegraph

Look, I know that I’m the voice of bitter old fans who think New Who was rubbish from conception, but I’ve stuck with the show and I want it to succeed. I also want it to be daring in more than just a visual or political way. I want it to be sophisticated, fun science fiction that opens kids’ minds to intellectual possibility. Maybe this new series will move in that direction, maybe not. But I will still be watching it. If only to find out what that crazy lady with the umbrella is up to.

Tim Stanley, Telegraph

‘Deep Breath’ is fun enough but is unlikely to become an instant classic in the same way as Smith’s introduction in ‘The Eleventh Hour’. Ben Wheatley’s superb direction keeps things creepy and adult. The special effects and cinematography are dazzling.

Meanwhile Moffat’s script is suitably darker and more mature to match the new Doctor, yet the Time Lord's dialogue is side-splittingly funny to balance the darkness. Within the story he even addresses everything from Scottish independence, the Doctor's age and Clara's relationship with the previous incarnation, which is an impressive feat in itself.

Neela Debnath, Independent

Capaldi plays the tartan time traveller as a serious thinker, an almost troubled being, with a burden. An independent soul, he is not ?nding his way in the world – he has already been there. In short, the new Doctor is one of us; older, kindly, grumpy at times, and with regrets. “I’ve made mistakes,” he says solemnly.

Once he gets over his post-traumatic regeneration disorder, this worldly Doctor could become a classic but do not expect the scarf to make a return. He may be an avuncular Doctor in a frock coat but he will not be reaching for the pipe and slippers.

David Stephenson, Express

Deep Breath is simultaneously familiar and yet unfamiliar. It’s a familiar ‘new Doctor’ episode which touches on the after-effects of regeneration. Steven Moffat’s clockwork droids from The Girl in the Fireplace return. And we’re reunited with the Paternoster Gang of Vastra, Jenny and Strax, who help uncover the droids’ murderous attempts to repair their spacecraft and reach the promised land. At the same time, however, everything is different. The Doctor himself certainly is, with both he and Clara struggling to come to terms with his new appearance and personality.

This is unmistakably a new style of story for a new Doctor. While there’s plenty of Moffat’s rapid-fire wordplay and humour, we’re no longer constantly hurtling from one hyperactive setpiece to the next. Instead the characters are allowed to carry the story. Will this continue when we return to standard length episodes? We’ll have to see.

Tim Liew, Metro

Not much is natural in Doctor Who. But Peter Capaldi’s debut as The Doctor was so astute and assured it quickly confirmed that he has the type of wily charisma that makes it a role he was born to play. In fact Capaldi was so confident about his selection as only the twelfth actor to portray one of television’s great icons that he even let himself be upstaged on his big night – not once but twice.

Capaldi’s low-key start was a welcome change to the zany antics of both Matt Smith and David Tennant when they burst into the show and which set the tone for The Doctor’s previous two incarnations. It was always hard to shake the suspicion that the way Smith and Tennant played The Doctor with such ostentatious gusto was more about making themselves popular than just playing him. Their grinning idiocy didn’t leave much room for The Doctor’s fabled gravitas, borne of 2000 years time travel. In Capaldi’s capable hands this will return, while The Doctor’s problems adjusting to his regeneration were less madcap and had more pathos.

All in all, it was an impressive, entertaining start for the new era, which will surely see Capaldi coming more and more to the fore.

Jim Shelley, Daily Mail

It's almost impossible to wade into Doctor Who. You can't just settle on the sofa and switch it on carelessly. If you're a novice you need to prepare. You must study the history and the recurring characters. It's like trying to understand the Second World War: you need to go back and understand the First, and to understand the First you need to go back further still and try to understand Imperialism and the intricacies of the European balance of power…it's exhausting.

You can't just turn up, fresh-faced and keen, hoping to innocently enjoy some Saturday night TV. There is just too much history and backstory with Doctor Who and it feels like it's groaning under the weight of its own continuity as well as under the demands of its fans.
Julie McDowall, Herald Scotland

I never had any doubt that Peter Capaldi would be brilliant. He is. On the evidence of Deep Breath, he’s the Doctor I’ve longed for since the series came back in 2005 – quite frankly, since 1981 when Tom Baker’s Doctor plunged to his demise. For many I’ve spoken to, he’s the perfect choice. They’re already convinced. But, in Deep Breath, the programme itself seems overly anxious that its now global audience won’t take to an older, craggier Time Lord. It is willing those millions attuned to, nay moistened by, the geeky good looks of Messrs Tennant and Smith to have faith in Capaldi.

Patrick Mulkern, Radio Times

As a standalone episode of Doctor Who, it had almost everything a fan can hope for. But more importantly, and more interestingly, it set us up for a turbulent series, which we now know culminates in the departure of Clara Oswald... although we don’t yet know how.

One certainty remains. Whether you love or hate Steven Moffat-written episodes, and in spite of Moffat’s love for neatly packaged, filmic individual episodes, he remains the master of the story arc.

If you watched Deep Breath and you don’t want to watch the rest of series 8, then there truly is something wrong with you (indeed, you may need help from a Doctor).
Richard Beech, Mirror

Never was it clearer that this was a regeneration, not a rejuvenation, in Doctor Who’s most hallowed traditions, that much will be demanded of its youthful audience. But, if the challenges may be great, so too will be the rewards. Judging by Peter Capaldi’s debut episode, the Tardis is, once again, in very safe hands.

Caroline Frost, Huffington Post

Capaldi’s incarnation of the sci-fi icon is a more mature, no-nonsense expression of Who-ishness, lacking the rubbery physicality of Smith but remaining as quick-witted and free spirited as ever. He’s a throwback to darker tones of the first few Whos—intentionally, per the behind-the-scenes feature that accompanied the episode. That modality is captured by the look he’s chosen for himself, a fitted long black coat streaked with crimson on the inside, suggesting power, danger, and a little whimsy. He’s a top hat and longer tails away from resembling an old-school stage magician. This is not another romantic, “boyfriend” imagining of Doctor Who, and it isn’t another reckless, rogue/borderline anti-hero version of the franchise, either. At least, not yet. “I’ve made a lot of mistakes,” he tells companion Clara (Jenna Coleman). “It’s time I did something about that.” We’ll see how that goes.

As bold and refreshing as this out-with-the-old, in-with-the-older regeneration promises to be, I resented the manipulative ways in which the premiere demanded we roll with things. The new era of Doctor Who should do the hard work of earning our affection and loyalty—not vice versa.

Jeff Jenson, Entertainment Weekly

He's woven the future from the cloth of the past. Simple, stark, and back to basics. No frills, no scarf, no messing, just 100 per cent Rebel Time Lord.

New Doctor, new era, and of course new clothes. Monsters of the universe, the vacation is over - Capaldi is suited and booted and coming to get you!

Peter Capaldi's Doctor is officially recorded in history today with the unveiling of his new costume. It's sharp, smart and stylish - The Twelfth Time Lord means business.

The most powerful moments in The Time Of The Doctor didn't involve a stand-off against intergalactic bullies and mad despots - they involved the Doctor reflecting on his time, and slowly giving in to the ravages of age. In this vein, Smith managed to wring genuine emotion out of his final on-screen appearance, but also nailed the quieter moments: the shutdown of a disembodied cyber-head is also the loss of a trusted friend.

(It) is a celebration of the recent past, and a dedication to the Eleventh Doctor, and his time in the Tardis. Time marches on for everybody, even Doctor Who, and everything eventually ends. While there is comfort in the fact that the story goes on, the Eleventh Doctor's time is over. It might have been silly sometimes, and the time-travel shenanigans often got overly complicated, but it was another fine chapter in the lives and times of Doctor Who. The next one is about to begin, but there is plenty of fun and emotion in the Eleventh's chapter that is worth celebrating.

I shed a tear in the knowledge that possibly the best Doctor the show has seen in its half century is no more. Smith had the ability to persuade his audience that he was, indeed, a millennium old man in a very young man's body. Well, on Boxing Day night on Prime, he discarded that body like a favourite suit too worn and raggedy to patch anymore. RIP 11. We are already missing you.

Smith is at his glorious best in this special, with plenty of reminders of why he might just be the best Doctor yet. Scrub that, he is the best yet and I'm going to miss his portrayal terribly.

The episode is ripe with writer/producer Steven Moffat's leitmotifs: messages sent across space and time, gatherings of The Doctor's rivals, small towns and sheriff badges. And some of the show's classic tropes: broken technology, the TARDIS telephone and lots of lovely one-liners. The risk, of course, is that the episode is so laden with in-universe references and nods to past episodes, moments, characters and aliens than it becomes almost impossible to navigate for someone without even a cursory knowledge of Doctor Who lore.

This is a pensive finish, but not gut-wrenching in the way that Davies wrote previous Doctor David Tennant's farewell. This is gentler, with only a cameo from his beloved Amy Pond (Karen Gillan) who says goodbye to her "raggedy man". Even Smith's lovely scene with old-school Fourth Doctor Tim Baker in the anniversary special was richer, and more touching. (And tearful, for Baker-era fans anyway.)

But salvation comes in the form of a gift, once promised (but never delivered) by the Time Lords to The Master in the 20th anniversary special The Five Doctors: a new life cycle of twelve regenerations. Which means that Peter Capaldi's Doctor becomes not the Twelfth Doctor, as previously thought, but the First Doctor, beginning a new chapter of life for the universe's most beloved Time Lord. And the comfortable assurance that his hope, his strength and, best of all, his eccentric madness, remains a light which will never be extinguished.

Even though the date of Smith's leaving and the identity of his successor, Peter Capaldi, had been known for some time, watching the episode knowing it was Smith's last kept at least one American viewer anxious and sad, with a finger on the pause button for when things got too heavy. Possibly there are still viewers, avid viewers even, who have never quite cottoned to him — Tennant continues to cast a long shadow — but I have loved his work. Elegant and heartfelt, authoritative and playful, swashbuckling and intimate, alien and familiar, Smith's acting has accommodated and, as it were, humanized every oddball, paradoxical, high-concept, low-humor passage Moffat has thrown at him.

It was always going to be so when facing the long-standing question of regeneration limits. Precedent for more regenerations being granted had been established before, and Steven Moffat led just about enough crumbs to the key moment to deal with the issue, without dwelling too much on it. Job done, whether you like the way it was done or not.

The Time Of The Doctor, then, brought the curtain down on what has to be classed as a successful 50th anniversary year for Doctor Who, that's had its bumps, but also given us some absolute treats. The Time Of The Doctor in itself is unlikely to go down as one of the Who highlights of 2013 in truth. We quite enjoyed it, but it still felt a bit underwhelming. Still, Smith's performance as the Doctor is undoubtedly one of the year's highlights, and it's very clear that the show is going to miss him a lot. What's also clear is that there are further exciting times ahead.

The lead writer achieves many things in this 2013 Christmas special: tying up straggly ends from Matt’s era – why the Tardis exploded in 2010, why Silence must fall, the big question that must never be answered… Points that most viewers have long since forgotten. The attentive fan is being serviced here.

Lots of ticks for advancing the legend of our hero and giving him a new lease of life. You can’t blame Moffat for taking on the responsibility – and allowing himself the honour in this golden anniversary year – of dealing with the “12 regenerations only” issue, which has dogged Doctor Who since it was established in The Deadly Assassin (1977). The future looks assured.

So farewell, fair Doctor! After 44 episodes spread across four years, magnificent Matt Smith discards his bowtie and lets it drop, poignantly, to the floor of the Tardis. And – after a rather protracted regeneration – in pounces Peter Capaldi. Gaunt, lizard-like and with frou-frou hair. Was anyone else put in mind of Doctor Pretorius from Bride of Frankenstein? I doubt Capaldi will portray his Doctor as a venomous dowager (unlike Ernest Thesiger in that 1935 black comedy) but I live in hope of a degree of archness.

let’s not forget Smith: he gave a cracking final performance before bowing out. He even managed to convincingly portray a wizened old Doctor. While David Tennant’s departure from the role of the Doctor was drenched in saccharine, self-referential sentimentality, there was very little of that in Smith’s final adventure. There were little nods to the 11th Doctor’s adventures and even a surprise guest appearance from Karen Gillan, who played his companion Amy Pond, but the nostalgia was reserved for Christmas.

Overall, as Doctor Who Christmas specials go, The Time of the Doctor was a sci-fi spectacular: there was time travel, spaceships and plenty of villains for the Doctor to face, including Daleks, Cybermen and Weeping Angels.

While some aspects of the story may have been lost on the casual viewer, it was nevertheless an adventure the whole family could enjoy.

Smith has been so good as the ageless, sinister, childlike, loveable alien that it was almost a shame to see that expressive Easter Island head caked in make-up for the middle section of this episode, while the swelling strings and Shakespearian speechifying of the final quarter-hour seemed comically at odds with the intricate lunacy that animates his best performances.

But there were some genuinely funny gags, Peter Capaldi looks promisingly demented in the role, Orla Brady was truly superb as a sexy spacefaring nun and the whole thing went off with as much of a bang for Smith as it could plausibly have done. I remain confused on a main plot point — if the return of the Time Lords would have started a war, why does no one bat an eyelid when the Doctor slaughters a planetful of Daleks with golden energy? But no doubt that, like so much else, has already been pitchforked laughingly into Later.

It was perhaps the most Christmassy Christmas special they've ever pulled off. I'm sure Doctor Who has thrilled me more in the past. It's certainly blindsided me more. And it may well have made me cry more, although it feels difficult to imagine such a moment right now. But I'm certain it's never managed to do all three so successfully at once. Merry Christmas. I hope we can all be there for each other at this difficult time.

The new (twelfth? First?) Doctor's arrival was quick and explosive. We didn't even get a changing-faces scene, which felt like an appropriate tease. But dear lord, he certainly looks like he's going to be angry. Should we wonder whether this new First Doctor is going to be based on the other First Doctor? Or are they doing a new, and hopefully better, version of the Sixth Doctor's violent, unstable regeneration?

This year's thoughtful Doctor Who managed to combine an 800th episode with a regeneration, then tied it all up with a Christmas Day bow. For his final episode, the BBC really got their money's worth out of Matt Smith, who carried much of the Time of the Doctor alone, and it was a neat trick to show the youngest ever Doctor getting old. Steven Moffat ticked all necessary boxes here: he answered the regeneration question (though it made little sense to this non-devotee) and gave incoming timelord Peter Capaldi a suitably sizable entrance: "Do you happen to know how you fly this thing?"

Easily the highlight of this year’s Christmas viewing, The Time of the Doctor not only gave Matt Smith a great send off but also gave viewers a careful, concise and emotional hour of top-quality entertainment. And as is typical for Who, renewal and regeneration are only the start of a brand new adventure, and from his brief introduction (“Kidneys!”) Peter Capaldi looks like a fine successor to take the world’s favourite TV hero in a different and equally exciting direction.

"The Time of the Doctor" was, if I'm being honest, kind of a let down as Matt Smith's final episode. It felt like it dragged a bit in the middle, and I never really cared about the town of Christmas or the Doctor being its savior for several hundred years. To be fair, I've been building this episode up in my mind for months, and it had to follow the well-received "The Day of the Doctor." It would have been nearly impossible for the episode to live up to expectations. There were aspects that I enjoyed however. The truth field was a nice touch, because the Doctor has never been a truthful man. He's skated by on lies and half-truths and being the smartest person in the room, so it was interesting to watch him simply have to stay quiet after several seasons of being a wound-up chatterbox.

Matt Smith's Doctor will forever be remembered for his eccentricities, for successfully filling the very large shoes of David Tennant, for his inability to talk without flapping his arms about, and for his love of fish fingers and custard, bowties and fezzes. But the most important aspect of his tenure was his relationship with Amy Pond, the first face Eleven ever encountered, and it's unfortunate that Smith's swan song was nearly devoid of any real emotion until the final few moments when she returned to say good night as he regenerated into Capaldi's Doctor.

Doctor Who is legendary, award winning, record breaking, and global, and this planet deserves something special and supernatural as its name, How better to honor its existence than by dubbing it the home planet of our beloved time travelling alien, The Doctor?

I'm like 1,995 years too young for the part, really! No, I think he's going to be quite happy to look his age at last! ... They are just one, but they're all of those actors, and they're all a delight, I think they're all fabulous, and I'm lucky to have them in my DNA, because I've watched it from year dot, so they're great.