Steven Moffat Introduces Knock Knock (documentary)
From Tardis Wiki, the free Doctor Who reference
Steven Moffat Introduces Knock Knock was a documentary detailing Series 10. It was part of a series of documentaries about series 10 of Doctor Who.
Main subject
Steven talks about the fourth episode of Series 10, Knock Knock, and discuss that we will find out why houses always creak and click, telling that it's not just the houses settling.