Last year friend of the blog Dan Martin took time to chat with Steven Moffat about the Doctor Who Series 7 Part 1 finale, The Angels Take Manhattan - and more specifically, "The Washington Theory". Dan asked the current showrunner why could Amy and Rory not just travel to Washington (or Boston, or anywhere for that matter) and meet The Doctor there? Had Moffat left a useful plot thread dangling to bring the beloved companions back in a couple of years? Not so, according to Moffat...
“New York would still burn. The point being, he can’t interfere. Here’s the ‘fan answer’ - this is not what you’d ever put out on BBC One, because most people watch the show and just think, ‘well there’s a gravestone so obviously he can’t visit them again’. But the ‘fan answer’ is, in normal circumstances he might have gone back and said, ‘look we’ll just put a headstone up and we’ll just write the book’. But there is so much scar tissue, and the number of paradoxes that have already been inflicted on that nexus of timelines, that it will rip apart if you try to do one more thing. He has to leave it alone. Normally he could perform some surgery, this time too much surgery has already been performed. But imagine saying that on BBC One!”
Moffat has also admitted that he changed the ending several times before filing his final draft stating, "To be honest they were all quite similar. There was a slightly more involved version which put River slightly more central. But I sort of realised I was trying to tell about four stories when two was quite enough. So I trimmed it down. Increasingly, the point of the story is The Doctor doesn’t really do anything for the second half except more or less complain and try to stop everything working. Obviously there was a point when he wasn’t like that, but I realised that that was the story. Once he realises he can’t escape the fact she’s going to leave him, he becomes sort of useless, and that’s the drama. And the dramatic heart of Doctor Who is very rarely The Doctor himself because he’s the man who fixes everything. This time he’s the man to whom it happens and that makes him interesting in a different way - and an amazing performance from Matt Smith as well.”
And what about return to the show for The Ponds? Moffat said, “You could never eliminate the possibility of dream sequences and flashbacks, but will the Doctor see them again? No. When I was first talking to Karen and Arthur about it, we said ‘let’s make it the proper ending’. Bringing back things just gives you sequel-itis. Just end it and get out. Heaven knows if they’ll appear in some form of flashback - I have no plans to do that I have to say - but the story of Amy and The Doctor is definitively over.”