I loved the episode but I fucking hated the ending. Them leaving together as the world ends is just dumb.
A much better ending would of been having the episode pay out as normal right until she closes her eyes and the World doesn't end. She calls Gaap who explains that everything has gone to plan and then the camera turns to the TV. Michael Smart is giving a speech from his hospital bed about how out of control immigrants are causing crime and attacking innocent people. Gaap chuckles and explains to Nida that because of her Smart gets elected and eventually becomes prime minister bringing hate, misery and death. After all, isn't that what Satan would want?
Why would Satan be working to save the world? Makes no sense?
Honestly, probably my favorite of the season! I don't think it's really Black Mirror, but it's fun.
Seeing a demon pushing a woman to murder people and still not having them look like villains is quite a feat TBH.
I kinda argree with @Striker that the ending fizzled out here. I think the best episodes have some sort of message at the end that comments on human nature. I'm not sure what that message was here - that one person couldn't save thousands by hurting a few? It felt like a lot of lead up to nothing.