Speaking to IGN in 2012, Karen Gillan said that she and showrunner Steven Moffat negotiated Amy's exit over a very pleasant dinner. She explained that she felt it was time for her to go, he outlined some upcoming plot twists, and they put their heads together. "He told me where the story was at and where it was going and then we kind of together came up with it," she said. "So it was really pleasant, actually. We had a lovely dinner and just kind of discussed what we both want and what's going to happen and then came to the decision."
But why did Gillan want to leave when she did? It was a gut feeling, she said. "It just felt right! I like to go on instinct." Amy had been through the ringer in the past season or so. She had gotten divorced, her child had been kidnapped, and things were looking down. That's why Gillan insisted Amy get a personally fulfilling ending. Gillan said that when the audience met Amy, "she was kind of in this lost, transitional period, where she didn't have a stable life. So I just want to see her get what she wants." And what Gillan and Moffat thought she really, truly wanted was a life with Rory.
