WARNING: Due to the nature of this episode, this review will contain spoilers - I recommend reading it after you watch the episode if you do not wish to be spoiled from any of the major plotlines present in this and the following episode.
Happy Hallowe'en! And what better way to celebrate the hallowed holiday than with an episode of Doctor Who written by the screenwriter behind last year's biggest audience-divider Kill the Moon, a monster returning after an unfinished subplot in 2013's excellent anniversary special Day of the Doctor with a returning guest star in the form of Ingrid Oliver's Osgood – last seen suffering Missy's abysmal puns before being solemnly executed during a terribly-planned scene by the unbearable Time Lady in Death in Heaven. So a potential misfire could be in the hands on this episode – despite the prospect of a Halloween story being a desired one (the only Doctor Who-related media to air on this date are the 1964 serial Planet of Giants and the pilot for the since-forgotten spin-off K9), but a defender of Kill the Moon – despite its absurd conclusion – and a fan of the Zygons, The Zygon Invasion has much to do to appeal...
Two years after the peace treaty between human and Zygon was established thanks to a trio of Doctors, and it's evident that the peace is beginning to collapse. With one Osgood already dead and another now captured by the Zygon resistance force, Earth is now at risk of full-blown war with the refugee race of shapeshifters, with secret kidnappings and replacements taking place worldwide and any settlements made being considered scum by the aliens – without the majority of the human race even aware of what's going on. And so the Doctor (Peter Capaldi) reunites with Kate Stewart (Jemma Redgrave) and her new adviser Jac (Jaye Griffiths) alongside a returning Clara (Jenna Coleman) to try and sort out peace before war can start out – not that the tough Colonel Walsh (Rebecca Front) particularly cares about keeping the peace.
While heavy with political allegories for the invading aliens, this first half does come on strong with new concepts (albeit unexplained as to how they're gained) and intriguing plot threads. Despite opening with a recap which feels a tad unnecessary – although needed for newer audiences who perhaps didn't watch The Day of the Doctor somehow – and the overbearing Osgood mystery of "which is she?" coming and going at an uneven pace, the pacing and actual storytelling involved is continuously good; only stopping when the more predictable moments for plot twists come to play. As a 70s episode of Doctor Who brought to life in the 21st century era, it's very well written by Harness – two for two in my eyes.
And as a fan of the Zygon race, it's good to report that they continue to thrive. The advancements into being able to mimic bodies from the memories of their prey and the removal of the weird addition of spitting out some form of liquid when they change form introduced in Day means that we have on our hands a brand new breed of the classic creatures; ones which benefit all the more and make even more frightening for younger audiences. Sure, it didn't stop Rebecca Front's colonel from wanting her soldiers to essentially kill their loved ones (that heartless person), but one person out of dozens of others? That makes the prospect a little more terrifying.
With guitar on hand and sonic shades still residing softly on his head (unfortunately), Peter Capaldi remains to be at his best; never diminishing in quality despite some of the more Matt Smith-esque moments such as comments about his undergarments or sitting around in a children's park talking to kids (at least it had some affect on the plot though, unlike the 2013 prequel to The Bells of Saint John), although in actuality his Doctor adds very little to the actual story bar saving an Osgood, having some discussions with the UNIT team and being part of a cliffhanger which does have a lot of anticipation (although let's face it, having that plane be destroyed so quickly after getting a new one post-Death in Heaven is bad on UNIT's behalf). Companion Clara is given a little more to do than usual; likely due to her increased role next week as one of the treacherous Zygons, which should lend to some great acting chops for Coleman after a period of just being there for the sake of her contract. Both Redgrave and Griffiths get something to do this time after the equivalent of a cameo in the season opener The Magician's Apprentice, with the latter still leaving some form of introduction or character understanding while the former just pleasing enough to have something to do for the first time since The Day of the Doctor. As for the very important Ingrid Oliver, she isn't as fangirl-y as previously due to the serious nature of it all, thank god, and the comedy actress does surprisingly fit the more dramatic role...although she doesn't actually have all that much screentime when you consider the fact that she's the central selling point. Front is a typical 'shoot first, questions later' character common in these kind of stories, but thanks to how prestigious she is she at least adds a touch of class to her role.
The Zygon Invasion is a surprisingly good instalment, marking the first time in numerous years that we've had three good episodes on the trot. Well-written by Harness despite its obvious political parallels and with a species of classic creations that continue to be strong with every passing appearance, we have an episode which opens strong. The question (not found on my underwear) is, will it be matched next week? 7/10.