Once upon a time, there were three Doctors and two Osgoods. Think back to the 50th anniversary special when the Doctor was dealing with the destruction of Gallifrey (the day when it was impossible to get it right) and the invasion of the Zygones. The Doctors decides to force the humans and Zygones to create a treaty by affecting their memory so that neither human or Zygone could remember their identity, thus forcing them to create a treaty that works for both sides.
Last week, Ashildr said that the Doctor solves the problems and then flies away leaving others to deal with the results. Well in
The Zygon Invasion we get to see the results of the Doctor's problem solving. In
The Day of the Doctor, two Osgoods were created when a Zygon took the form from the human Osgood. In the present, the two Osgoods speak about operation double which was created to resettle and rehouse an alien race. With Unit's help, 20 million Zygones have taken human form and are now living on earth. The Osgoods are making this recording in case something goes wrong and Unit is infiltrated or one or both of them dies.
We then flash to a scene where one Osgood stands in front of a tombstone which is inscribed with the word sister with no date of birth or death. The dead Osgood was killed by Missy.
Back to the recording where the Osgoods both claim that the Zygones are a peaceful race. They claim that shape shifting is a survival mechanism and that any race is capable of the best and the worst. The Osgoods claim that if one Zygone or on Human goes rogue, it will destroy the peace treaty. It seems that the Doctor left the Osgoods, the Osgood Box and it is the last resort - the final sanction. Both Osgoods say that if the box is ever needed, it would be a disaster; it would mean war.
Osgoode is now in a war zone and she rushes into a building to hide. When a Zygone approaches, she tries to hide under a desk. Osgood uses her inhaler and then frantically pulls out her phone to send a message to the Doctor. The Zygone enters the building and then pulls Osgood out from under the desk where she is hiding and then zaps her in the forehead.
The Doctor is in the Tardis playing
Amazing Grace on his guitar when he receives Osgood's message about the nightmare scenario. Is every episode going to have Capaldi playing the guitar now?
The Doctor is in Brockwell Park, London. Several school age children mill around and the Doctor sits on a swing. The Doctor calls Clara, calling himself Doctor Disco and says that he staking out some of the most dangerous people imaginable. The Doctor takes off his glasses (yes, the Doctor is still wearing the blasted sonic sunglasses. A pox on Moffat) and approaches two little girls who are playing on the monkey bars, telling them that they need to talk.
In the Unit safe house, in south London, Kate Lethbridge Stewart is trying to plan what to do next now that one Osgood is dead and the other is missing. Kate watches a video of Osgood being taken away and learns that the encryption system for Osgood's files have been hacked.
On the playground, the Doctor informs the kids that he knows that they are Zygones but they ignore him and play. The Doctor says that he knows that the factions which the twins don't control are planning something. He warns that if they don't do something the peace will end. One of the girls tells the Doctor that this is their jurisdiction and that are close to finding the rebels. The Doctor replies that he is taking this out of their hands and steps away when his phone rings. It's Kate, who informs the Doctor that the cease fire has broken down. Suddenly, red smoke appears on the playground and the Doctor rushes to the two little girls. Zygones appear out of the smoke, snatch the girls and then drive away in the truck, leaving behind a claw like mark.
The Doctor and Kate watch a recording of Osgood. Two Zygones stand guard as Osgood says that the war is about to begin and that those who oppose the Zygones will be destroyed wherever they are. Osgood says that there will be truth or there will be consequences. The Doctor calls Clara and once again gets her answering machine. The Doctor leaves a message demanding that Clara call him now.
Clara returns home and when she checks her phone, she notes that she has missed 127 calls from the Doctor. Clearly something is up. I cannot imagine the Doctor calling even one time and Clara ignoring him, particularly given how close they have become recently. Clara quickly hangs up the phone on the Doctor when she sees a dejected Sanjeep sitting on the stairwell. The little boy says that he cannot find his parents, so Clara instructs him to wait there while she has a look. Clara enters the child's apartment and is approached by two Zygones masquerading as Sanjeep's parents. The child screams but Clara is told that everything is fine. When Clara leaves the apartment, she gets another call from the Doctor.
Clara and the Doctor meet Kate at Drakeman Junior School - the Zygone headquarters in Dulwich London. Kate explains the treaty to Clara and the Doctor and says that he left them with an impossible situation. Yep, remember what Ashildir said last week. The Doctor simply calls it peace and asks about the two little girls. Kate answers that the girls were impossible to deal with since Osgood left and that there's a revolution brewing in the younger brood. The Doctor says that the Osgoods were the peace because they were Zygone and human at the same time. The Doctor learns that when one of the Osgoods died, the other went mad with grief. Touching the control pod for all of the Zygones on earth, the Doctor learns that the Zygones are starting to worry. The Zygones hatched and dispersed but something has gone wrong and they are worried about what would happen if the humans knew who they were.
They get another video from the Zygones which says that their rights were violated and that they demand the right to be themselves. They force the two little girls to take their true form and then slaughter them. The Zygones say that they will kill all traitors and finish with the words, "truth or consequences."
The Doctor wants to open negotiations but Kate refuses to do so. Kate wants to bomb Turmezistan. The Doctor points out that the problem is a splinter group and that if Kate starts bombing, the rest will be radicalized. Clara pipes up to say that Truth or Consequences is in New Mexico and she knows this because it's a Trivial Pursuit question. It seems that Clara's little hobby is memorizing the answers so that she can win. The Doctor sends Kate to Truth or Consequences to negotiate peace and rescue Osgood. Clara and Jack are told to stay in the U.K. because this is their country. The Doctor asks about his the presidential aircraft because he likes flying about in a big plane.
The Doctor boards the plane and Kate says that they don't have many troops. Kate talks about a previous invasion in which a member of their staff created a nerve gas to take out the Zygones but it was stolen by somebody with a Tardis. Yes, they are talking about the same gas Harry Sullivan created to turn the Zygones inside out after he was duplicated by them (classic who, 4th Doctor). I guess that's one way to get even.
Clara and Jack head to her home to grab a couple of things. They come across the zygones dragging out the little boy wrapped in a carpet. Clara's big plan is to catch up to the elevator and she and Zack race down the stairs. Clara notes that the elevator is slower than usual and when the doors open, the elevator is empty. Clara and Zack enter the elevator and the doors close. Something starts to ooze out of the control panel of the elevator and when Clara opens the control panel. she sees Zygone parts. Clara touches it and the lights go out and the elevator starts to shake. When the elevator door opens again, Clara and Jack cautiously step out. In the distance, they hear the screams of the little boy. They see the zygones in their true form, so Clara suggests that they need reinforcements.