I wasn't really aware they were a religious organization for quite some time. But my grandparents were very devout and ran a Quaker meetinghouse and were missionaries at one point.

What happens often is the script is written and once the director comes on board you have lots of conversations and it mutates again.

"Be Right Back," in which Hayley Atwell brings Domhnall Gleeson back from the dead using his social-media profile, sprang out of an unrelated conversation. Other stories you thrash away at for weeks and weeks.

When you look at things like social media, that's an immensely powerful tool that I'm all in favor of. I think it's amazing. It's a powerful tool, and it's one that we're, as a species, still grappling with learning to use. It's like we've grown an extra tail and we inadvertently lash out and knock over all of the furniture.

The logic for me, in writing it is that the different areas or different years are almost like different rooms.

In comedy writing, a sitcom plot is basically the same thing: What's the worst thing that could happen? But you're playing it for comic effect. It's a similar muscle being used with Black Mirror.

We take things that would have struck us as miraculous five years ago for granted. Like Pokémon Go would have been insane, and now it's just like, "Oh, okay."