Reviewed by John Hussey.

As Steven Moffat promised prior to Series Nine starting, he had discovered a means to prevent the usual mid-season dip by throwing in a Zygon two-parter.

Bizarrely these creatures have stood the test of time through being remembered in an iconic fashion despite only ever appearing in one serial during Tom Baker’s reign as Doctor, namely ‘Terror of the Zygons’. Then, nearly 40 years later, they represented Doctor Who’ 50th Anniversary as the Eleventh, Tenth and War Doctor’s adversary during the ‘The Day of the Doctor’.

The 50th Anniversary set up an interesting storyline concerning the Zygons. Some, including myself, felt cheated by the abrupt ending to the Zygon storyline during ‘The Day of the Doctor’. It seemed out of place with the main narrative (namely the War Doctor’s decision of whether or not he should activate the Moment), made worse by the fact it concluded rather badly. However, that little flaw isn’t a flaw anymore as the story has now continued almost two years later.

It was nice to have the pre-credit sequence make physical reference to ‘The Day of the Doctor’. Seeing Matt Smith, David Tennant and John Hurt playing the Doctor again was a breath of fresh air, and reminded us how good 2013 was for Whovians. It also made the Zygon subplot of the 50th have more depth and meaning. Now in 2015 we have the conclusion. As indicated in ‘The Day of the Doctor’ the Zygons and humans were left on good terms and peace was thought to have been reached. ‘The Zygon Invasion’ showcases that the Zygons were allowed to stay on Earth in secret under the condition that they remained in human form.

But, as it is quickly established, the peace treaty doesn’t remain stable for very long. Rogue Zygons fight for their rights by whatever means necessary. We gained a narrative that screamed out references from the glorious Jon Pertwee era. We had UNIT, the Doctor working with a Lethbridge-Stewart, an Earth invasion, and a political dilemma. The Pertwee era often put into play political undertones that made you question current situations. ‘The Zygon Invasion’ does a great job at making you question which side is right. Are the Zygons truly evil in wanting equal rights?

The questioning is made worse by the simple factor of the Zygons being shape-shifters. You never know if the character onscreen is who they say they are. The narrative becomes a massive thriller, with a global threat that reminds you of Terrorist warfare. We have the rogue groups killing innocent people, making warning videos that describe their course, along with the paranoia of military intelligence becoming panicked and retaliating with brute force. All these elements, brought together wonderfully by Peter Harness, created a tense atmosphere throughout.

It was nice to have both a traditional UNIT story and an Earth invasion story. These two story types had become rare within the New Series and barely got done right. They either featured UNIT in a weakly written way or the Earth was invaded by an iconic villain, usually the Daleks. So it was nice to see ‘The Zygon Invasion’ take a fresh spin on things. Though the Zygons are iconic figures in Who mythology, they haven’t been used much throughout the show’s history and so remain fairly new and intriguing. Plus their ability to shape-shift, as mentioned above, creates a unique narrative that creates an invasion of paranoia and deception.

The Doctor and UNIT, both being in on the Zygon/human peace treaty, now have to work carefully to ensure peace remains. Protocols, as indicated by Osgood in the pre-credit sequence, have been put into play. If any of these protocols are breached then war is waged. What made the narrative better was the global scale of the entire episode. This was made by the fact that the different characters were split up to investigate different parts of the continent.

I liked how Peter Capaldi got to work with Rebecca Front again, his fellow co-worker from The Thick of It. Instead of her playing a dysfunctional MP being shouted at by Capaldi she instead played a confident character, who is slightly trigger happy in her duty. Once again she and Capaldi played off each other well, formulating a great onscreen chemistry. The Doctor is constantly trying to battle against Colonel Walsh as she tries to approach the battle against the Zygons in a hostile manner. Her view points are understandable due to the dire situation, especially after her men were killed in the most personal manner possible. At the same time you have to take the Doctor’s stand point in wanting to keep the situation as calm as possible. Upon retaliating you give in to the enemy’s desire and ignite the fire further, granting the Zygons the perfect reason to fight back.

Another great factor was Kate Stewart finally getting some good material. I felt that her small cameo in ‘The Magician’s Apprentice’ was pathetic, and completely disrespectful to both the character and Jemma Redgrave. Apart from a few interesting scenes, and lines of dialogue, during last year’s ‘Death in Heaven’ she again wasn’t used to the best of her abilities. Finally Harness uses her properly and allows her to actually take centre stage. Redgrave is a fantastic actress and understands her character well. I always like seeing Kate return. Her character is special, especially through her connections to the past. Kate and the Doctor share a unique bond, similar to that the Doctor used to share with her father, the Brigadier. It’s also nice to see her expand into the Big Finish universe with her own series, UNIT, with the first boxset (‘Extinction’) due out this month.

One of the things that confused me during the build up to Series Nine was the return of Osgood, who had been killed off by the Master in the previous series. Speculation arose about whether or not the Osgood killed was her Zygon duplicate seen in ‘The Day of the Doctor’. It was clever to use the two Osgood’s as a key factor within this narrative. Continuing this year’s vague story-arc, “the Hybrid”, Osgood becomes the next spectator, after Ashildr, for the supposed spliced DNA hybrid between two powerful species. This was first mentioned by Davros in ‘The Witch’s Familiar’ and teased that this prophecy was what made the Doctor run away from Gallifrey in the first place.

Osgood is now identifying herself as a new hybrid and appears to be the key factor between the two species. Also there is the strange device, given to her by the Doctor, which could possibly end the war. As to what it does is unclear but I imagine it isn’t a good thing. There was a nice little tease as to whether the real Osgood is dead and at one point it is almost made clear which one died before the Osgood onscreen makes it vague again. This was another clever thing to do because it left fans to speculate their own ideas and theories on which Osgood is alive and which one isn’t. As it stands, it’s still up in the air but as both Osgood’s seemed to have been connected somehow, it’s fair to say it isn’t easy to answer that question anymore.

I did begin to think that Clara was really bland this week, showing almost no signs of emotion. This is something that had been troubling me about her this series, and apart from the opener, has become extremely alien in characteristics and hard to identify. This made Maisie Williams promotion to one-off companion last week a nice little change. But, as it turned out, there was a reason for this in this particular episode. This led in to the massive cliff-hanger which I didn’t see coming. It really made this two- parter darker and more twisted. It became a gritty thriller which made you anxious and on-edge. The Doctor has no control over the situation, even with his “President of the World” badge on.

Verdict: 10/10

The Zygons are a cunning creature and have been used wisely to tell a great tale in which the Doctor is challenged. ‘The Zygon Invasion’ wasn’t just your usual alien tries to kill everyone and the Doctor stops them story. It was deep and well thought out, generating a tale filled with paranoia. The Earth was in mortal danger in the scariest way possible and I really can’t wait to see how this narrative concludes next week.