It is World War II and Madge Arwell is trying to hide from her children the awful news that their father, a British bombing pilot, was lost over the Channel during a bombing mission. It is Christmas Eve and she doesn’t want to spoil Christmas for them.
“I don’t know why I keep shouting at them,” she says, bottom lip trembling as she tries to put on a brave face.
“Because every time you see them happy you remember how sad they’re going to be. And it breaks your heart,” replies The Doctor. “Because what’s the point of them being happy now if they’re going to be sad later? The answer of course, is that they’re going to be sad later.”
–Doctor Who, The Doctor, the Widow and the Wardrobe (Christmas Special, 2011 BBC)