Doctor Who: Series 9 Episode Titles And Plots Announced
6. Episode 7: The Zygon Invasion
This episode is penned by Peter Harness, the man who made the Moon an egg for a giant space chicken in last year's Kill The Moon. But, on the other hand, Zygons, so... let's hope for the best, eh?
There's an intriguing dialogue quote for this story (from almost certainly Kate Stewart):
"Operation Double is a covert operation, outside of normal UNIT strictures, to resettle and rehouse an alien race, in secrecy, on planet Earth."
We've known for a long time that this season would see the return of semi-regular character Osgood (Ingrid Oliver), and this two-part story is where she features. As Moffat's summary points out, she died the last time fans saw her.
A long time ago, the Doctor made a deal in the Tower of London. 20 million Zygons walk among us, in human form, living undetected in peace and harmony. But cracks are showing in this delicate peace. Humans and Zygons are disappearing. In city apartment blocks, lifts are going missing, and far below the streets of Britain, alien pods are growing in secret caverns. UNIT's scientific advisor, Osgood, sends a desperate message to the Doctor - but since Osgood is long dead, how is that even possible?
The mention of "pods" raises the possibility of a third force at work, and a new alien race for Doctor Who. It all sounds very "Invasion of the Body Snatchers" and that's not a bad thing.