Spoiler alert, starting NOW!
The 50th anniversary was supposed to be a stand alone episode. Or so we thought. Right away we see flashbacks about what happened with the Zygons. We knew they’d have to address this eventually, and here it is. Not when I was expecting it, just like Moffat wanted.
Osgood and her Zygon twin made a video to neatly explain current events for us. It’s been decided that 20 million Zygons will take human form, live on Earth among the humans in peace and the treaty will be maintained. In case anything happens to either or both Osgoods, this tape has been made to explain things. There’s a box the Doctor(s) left behind in case things go south, but we aren’t told what’s in it. At the beginning of the season when Missy killed Osgood, I kind of wondered if it was Osgood or a Zygon, but it wasn’t addressed. Now we see an Osgood standing in front of her “sister’s” grave. But which Osgood is still alive? The one standing there is *not* wearing a scarf, so I wonder if we lost the human one?
We next see an Osgood running/hiding from a Zygon. She attempts to text the Doctor but the Zygon catches/kills her. Flash to the Doctor and he’s playing his guitar again (Amazing Grace) when the text “Nightmare Scenario” arrives. He heads over to check things out. By check things out, I mean he chases down a couple Zygons posing as 7 year olds and tells them he’s taking over.
We next see Kate Stewart making plans. If you look carefully, there’s Easter eggs lurking in this scene, like a picture of the first Doctor on the wall. It appears Osgood hasn’t been killed, just captured. Unfortunately her data containing the location of every Zygon has also been compromised. Kate tells the Doctor all of this, and he finishes up just in time to see the two girls snatched by some other Zygons. It appears they’re collecting all of their “kind” for some reason.
The Doctor meets up with Kate (UNIT in general) and Clara’s still not answering her phone. Wait, maybe Clara is a Zygon… We flash to Clara just in time to see her realize she has 127 missed calls from the Doctor. She gets side tracked in her building with a little boy (who I think just got taken by Zygons) before returning his call and meeting up with him. Once they head over to the Zygon command center to investigate we have time to find out that after the truce they never learned which Osgood was the human and which was the Zygon. Turns out, they were both a bit of both. When one died, the other went mad with grief and went into hiding… Could she be behind this?
The Zygons have been sending UNIT a series of videos, like with Osgood reading a threat. Now there’s a new one with the two little girls (who are actually the Zygon high command) being vaporized. The radicals have taken over. Despite Kate’s first instinct to start a war, the Doctor sends her to New Mexico to investigate, Clara is going to stay to be a base of operations, and he wants to take the presidential plane to go negotiate peace. Doubt that’ll work out. Kate said that they had nerve gas that worked on just the Zygons but the Doctor had taken it. If I remember correctly, that was actually during an “old Who” episode.
Clara wants to swing by home to grab some things with Kate;’s assistant (Jac). The first thing I thought of was her neighbors and the potential Zygons. Sure enough, within seconds we see the neighbors hauling a child-sized sack into the elevator. They run to chase the elevator but it’s empty. So they get in, discover a Zygon control panel behind the floor selector and end up in some underground base… of course the neighbors are just ahead. Smartly they run away.
At the Doctor’s location he tries to stop UNIT from blowing up the town in New Mexico. The agent that was supposed to be carrying out the order only stopped because she saw a man and child that looked like her family. So would she be killing Zygons, or is it her family that are the Zygons?
In New Mexico, Kate meets the local law enforcement. Meanwhile, Clara and Jac discover that elevators are going underground with bundles all over the UK. Bouncing back to Kate (all this bouncing around is making my head spin) it appears a bunch of Brits appeared there a couple years prior then started taking Zygon form and came after the locals. But Osgood was there just before everything went down.
The Doctor and UNIT head to a Zygon occupied village to try and collect Osgood. The UNIT soldiers get tricked into believing the Zygon imposters are family members, follow them into a building and end up as piles of electrified remains. The commander and the Doctor are all that’s left. The commander leaves the building where the remains are, and the Doctor finds Osgood chained in the cellar. Time to go…
The officer with Kate shows her a dumpster full of remains, left behind from the Zygons. Close by, there are 4 more of them. So a whole town basically. The Doctor also has a chat with Osgood and we learn that Zygons no longer need to keep humans alive to keep their faces. Now they can wear a memory, providing they don’t need any further information from the original. So we still don’t know for sure which she is.
Clara’s group heads back underground and discovers a bunch of Zygon pods. Clara leads a UNIT group in to neutralize them when she discovers *herself*. YES! Jac is even smarter than she looks and quickly realizes it’s a trap. But too late! They’re all killed…
Flashback to Clara in the neighbor’s apartment, and she was actually captured and replaced by “Bonnie”. Flash to the Doctor talking to a Zygon prisoner and they say they’ve already taken over… Flash to Kate and she finds out that her new friend is also a Zygon. Not a surprise – why would a town full of Zygons leave one human?
Back to the Doctor and Clara (back and forth) and Clara (Bonnie) sends a missile at the Doctor’s plane… Nice way to end an episode!