The Doctor: There’s a portrait on the wall behind me. Looks like you, but it’s too old, so it’s your father. All the chairs are angled away from it. Daddy’s been dead for 20 years but you still can’t get comfortable where he can see you. There’s a Christmas tree in the painting but none in this house on Christmas Eve. You’re scared of him and you’re scared of being like him and good for you, you’re not like him, not really. Do you know why?
Kazran Sardick: Why?
The Doctor: Because you didn’t hit the boy. Merry Christmas, Mr Sardick
As someone whose grandmother yelled “leave the boy alone” as my father beat me as a child, I couldn’t stop crying at that sentiment when it aired. Thinking about it makes me tear up.