DOCTOR: I mean, basically the code came from nowhere, but then so did the universe, and no-one complains about that.

JOY: She died on Christmas Day. On Christmas Day! I said goodbye on an iPad! Because of the rules! She died alone! And those awful people and their wine fridges, and their dancing, and their parties, and I listened to them, and I let my mother die alone! So I can never be home on Christmas Day, and I can never be with anyone on Christmas Day because I let her down. I let her down on the last day of her life, on Christmas Day. I can’t ever change that. I can’t ever change it.