Another blank space in the narrative of Doctor Who, 'The Day of the Doctor' didn't explain how the Zygons successfully negotiated a treaty with UNIT. The suggestion of "peace for our time" from Eleven wasn't the most encouraging thing he's said, given that these were the exact words Neville Chamberlain used about the Nazis in 1938; the Zygons definitely have another story in them, don't they? This would be the perfect catch-up with a villain, answer a question about 'The Day of the Doctor', and set up a Series 8 story. It's not just the Zygons though; there seems to be a story waiting to be told about Osgood, and now that Moffat has established UNIT fully, who's to say they won't play a huge part in the Capaldi era? Maybe the Jon Pertwee influence doesn't stop at his new coat... Likelihood: 5/10
