Solid UNIT story all things considered! I loved how squelchy the Zygon ship was, I truly have a fondness for spaceships that are full on just Fleshy. Apparently though nobody can write a Zygon story without it being weird politically - oh so there's a ship full of what are explicitly stated to be refugees and they can look just like you (bad thing! can't see them coming!) and they want to turn this place into a replica of their home? Is that the message we're going for here?