Dear Dad,
This is the difficult bit. If I got this right, you’re reading this a week after we left in the TARDIS. The thing is, we’re not coming back. We’re alive and well; stuck in New York, 50 years before I was born. I can’t come home again, I won’t ever see you and that breaks my heart. I’m so sorry, Dad. I thought about this for years and I realised, this is what I could do, I could write you a letter, tell you everything about how we lived, about how, despite it all, we were happy. But before I do, I need you to know, you are the best dad any son could have had. And for all the times I drove you mad and you drove me mad, all the times I snapped at you… I’m sorry. I miss everything about you, especially our awkward hugs. I bought a trough, we have a small yard, I garden. But one more important bit of business, the man who delivered the letter, Anthony.. be nice to him ‘cause his your grandson. We finally adopted in 1946: Anthony Brian Williams. He can tell you everything, he’ll have the family albums and I realise having a grandson who’s older than you is so far beyond weird but I’m sorry.

I love you, Dad. I miss you.