The Zygon Invasion is, as Steven Moffat put it, a “love letter to Doctor Who fandom,” taking some of the fiftieth anniversary special’s premise and characters and expanding their presence in the Whoniverse.
While the return of popular character Osgood, herself an homage to the show’s dedicated fanbase, was great, she so far is a plot device, a bread crumb trail leading to the Zygon threat permeating the world, a covert resettlement operation embedded while the regenerated Time Lord was hopping around time and space. My hope is that her significance, as opposed to any other character that could be used, will become more evident in next week’s The Zygon Inversion.
One of the most pivotal moments for me in this episode was the attempted UNIT strike on two Zygons bearing the faces of the soldier’s own family. The Zygons bear a great tactical advantage in manipulating human emotion and attachment by assuming the faces of humans — while the anniversary special didn’t utilize this to its fullest potential, this episode did, detailing the emotional conflict, confusion, paranoia and fear one would face in this kind of event through several characters. In this way, the episode could even be seen as a sort of political statement, an attempt to refute those blaming or threatening the entirety of a group for the actions of a few.
While the Doctor’s initial reaction comes across as distant and analytical — a reminder that though he fights for humanity, he himself is not human — he settles more into his true disposition of attempting to save the world, though his lack of interference with the revenge-seeking colonel and her cut-throat orders seemed a bit out of character, something previous incarnations of the Doctor wouldn’t have hesitated to fight against.
The Zygon Invasion, alongside the previous two, also starts to show Clara’s growing independence from the Doctor, essentially leading to her series-ending exit, whether in the form of a willing departure or otherwise. And while this separation of the Doctor and his tied-at-the-hip trusty companion is a break in formula for the show, it’s giving both characters the opportunity to develop individually and show new capabilities and facets of their personalities. However, the episode doesn’t simply allow Clara to carry on a normal life away from the TARDIS, making sure to remind her that, even if the Doctor isn’t there, the trouble he causes or must resolve is always present, and as long as she travels with him, she will always be in the path of danger.