- You may be looking for the real world television story.
The Zygon Invasion was the seventh episode of the ninth series of Doctor Who. It followed The Woman Who Lived and was succeeded by The Zygon Inversion. It was first broadcast on BBC One at 8:15pm on 31 October 2015 and was forty-six minutes in length.
Behind the scenes
This is a in-universe counterpart of the real world Doctor Who television story The Zygon Invasion that exists within the Doctor's universe. It was a visual meta-fictional cameo in The Zygon Isolation, where Petronella Osgood and her Zygon duplicate scroll through BBC iPlayer searching for something to watch.