This item Contains Plot Spoilers
Press reaction for the The Zygon Inversion is mostly positive with many reviewers picking up on the performance of the lead actor. Peter Capaldi's finest hour is how The Express describes the episode. "Peter gives a powerful performance as a Doctor trying to maintain a fragile ceasefire, opting for diplomacy over militancy. Throughout his speech, he never loses his flow or passion. At times it feels as if the television screen falls away and we're watching a stage production, such is the strength of his acting."
The Guardian felt the episode finally cemented Capaldi as The Doctor. "As he delivered his passionate, eloquent takedown of Zygon rebel Bonnie, this version of the Doctor was comprehensively nailed, skewering perfectly who this man is.....This Doctor has never been written better, Capaldi has never channelled Tom Baker more, that sequence is cemented instantly as the “Capaldi moment” in clip shows for the rest of time."
Digital Spy agreed. "Peter Capaldi is absolutely spectacular.His emotional, grandiose confrontation with both Kate and 'Zygella' is spellbinding. A breathless, breathtaking lecture on the futility of war, this sequence is easily Capaldi's finest moment as the Doctor since he took up the reins last year."
Radio Times thought the bunker scenes between The Doctor and the two protagonists were spectacular. "An incredible piece of writing and acting. The scene lasts a full ten minutes as the Doctor runs the gamut of emotions in his effort to make Clara/Bonnie/Zygella stand down and “break the cycle” of cruelty and war. The Time Lord and the writers (Peter Harness and Steven Moffat) are wearing their hearts and political colours on their sleeves. It’s wonderful to watch and absorb."
The Metro also loved the Doctor's speech. "The use of the Osgood boxes – mere McGuffins to force both sides to think and talk for long enough to defuse the conflict – is a typically elegant Doctor-style resolution. They are no more than empty vessels that allow him to channel his preferred weapon: the power of words." The paper felt the episode so nearly a classic. "The story lacked the visible large-scale threat – it was all implied and never seen – and an iconic moment that, say, an army of Zygons marching across London would have provided."
The Telegraph thought the episode over complicated "Putting paid to the threat involved negotiating over an "Osgood Box" which would either do away with all the humans on Earth or all the Zygons. But the box turned out to be two boxes… and each box contained two buttons. In other hands this might have been a deft sequence of plot switcheroos, but here it felt like stage business to pad out a slightly threadbare symposium on terrorist ideology"
Online Den Of Geek joined in the praise for the show's lead actor and the themes pursued in the story. "Doctor Who has just blasted a 45 minute lesson in tolerance, the state of the world, war and the futility of conflict straight into people's living rooms while The X-Factor was on the other side."
The themes of conflict were picked up by AV Club. "The climax of The Zygon Inversion makes explicit something that the best anti-war Doctor Who stories have always understood. Depicting the madness of war doesn’t require an epic scale. If anything, narrowing the focus to a single conflict or moral dilemma clarifies the essential futility of violent conflict."
IGN concurred "It takes the Doctor’s painful recollection of the war he fought in -- the ultimate war -- to convince Evil Clara, to get her to start to see things his way. “When I close my eyes, I hear more screams than anyone could ever be able to count,” he says. And suddenly Evil Clara isn’t so evil anymore, as she realizes her and the Doctor are more alike than they are different."
TV.com enjoyed the darker tone of the episode. "The magic of Doctor Who is that it's constantly able to reinvent itself, and so it has. I wish that I could sit back and just enjoy the innate silliness of some of the show's lighter episodes, but given the darkness that permeates much of the Capaldi era, I find myself drawn to the episodes that have deeper meanings, that touch on the more serious subject matter at hand."
gamesRadar felt the highlight of the story, and even the series, was the interaction between Clara and Bonnie. "Jenna Coleman manages to make them feel like subtly distinct characters, and has a blast playing against herself in one (or should that be two?) of her best performances of the series" Mashable also praised the performance of both of the lead actors. "Jenna Coleman manages to thoroughly convince as both sides in the Clara-Bonnie battle of wits. A showdown conducted over a television could have easily looked laughable, and Coleman deserves the credit for making it work."
TVFanatic preferred the first episode of this double parter. "Bonnie forcing that Zygon out of his human form was freaky, but the morphing was not smooth at all. It would have been preferable for the man to stay in that inbetween state, which was fairly disturbing. True, the point was for the alien footage to go viral. Still, I'm just not a fan of the Zygons" The Register also felt the episode to slow "The Zygon Inversion feels a little too laboured, overly-wordy and lacking in action, and that's despite a tremendous performance from Peter Capaldi. A pity, too, to see such a brisk demise of the excellent Bonnie."
Finally Radio Times loved the past references in the story. "A punch-the-air moment for the Doctor Who fan. In case you don’t know, Kate’s dad, the Brigadier, issued the command “Chap with the wings there. Five rounds rapid!” in the 1971 classic The Dæmons"
You can read the Doctor Who News review in our reviews section.